ConfusedFriend87, I will make an attempt to respond to your concerns as both a Survivor of domestic violence/abuse and as a volunteer counselor.  Some of what I will type may not be what you wish to read, but it's based upon Truth, so I hope that you take it for whatever it's worth.

Red Flag #1:  "...Apparently there's medical evidence- photos, x-rays, all proving that he's been hurting her." 

Red Flag #2:  "...but she's a crazy bitch so I believed him when he said he hadn't hurt her..."

Red Flag #3:  "...And I'm afraid if I abandon him, he'll try to kill himself again, since last year he had a very serious suicide attempt that scared the crap out of me..."

In reference to #'s 1&2, "apparently" means that you are STILL in denial about his true nature.  There is no such thing as "almost pregnant," and there's also no such thing as "apparently abused."  Medical evidence does not lie - if it were self-inflicted, medical personnel would be able to clearly recognize self-inflicted injuries.  Trust me on this.  She's a crazy bitch, honey, because she's being abused and the ONLY WAY that she can maintain any control in her life as a victim of domestic violence/abuse is to act-out against others.  I was just such a "crazy bitch" and your language suggests that you believe that she (or, anyone else) somehow deserves to be battered. 

In reference to #3, you are a victim of abuse, as well. Being abused doesn't always entail physical battery.  There are many, many forms of abuse, such as physical, mental, emotional, verbal, spiritual, sexual, and financial.  That you somehow are feeling responsible for his suicidal choices is evidence of another form of emotional abuse and control.  YOU ARE NOT RESPONSIBLE FOR HIS CHOICES.  What he chooses to do is in direct relation to the reaction that his actions will create among those who mistakenly care deeply for him.  He is using YOU as a tool to satisfy whatever need he gets from his association with you.

Finally, the fact that he has vehemently denied his violence bodes very ill for his possible recovery as a perpetrator of domestic violence/abuse.  If you still care for this individual, you will have to make some very important choices for your Self (Self is that Life's Spark which makes YOU unique in all the world).  In order to protect your Self from further use/abuse, you may want to suggest that he seek intensive abuse counseling, in no uncertain terms, and that the safety and future of your relationship with him depends upon his involvement in therapy/counseling with an abuse specialist.  Whether he has endured a dysfunctional or abusive upbringing, sexual battery, or the Moon rising in Venus the day of his birth is not an excuse for perpetrating abuse and violence against another human being.  It may be a reason for his choices, but it is not an excuse - I came from an extremely dysfunctional background and I have managed to walk the path of healing in the best way that I can.  He must be responsible for his own choices, my dear.  If he chooses not to engage in counseling/therapy, walk away from him and never look back.  It's just a matter of time before he permanently damages or kills someone - maybe, even you if you present a threat to his control.  There have been 2 murders in the past year in our rural area that are a direct result of domestic violence and abuse.  Murder is NOT unusual, as you will learn when you check out the sites, below.

Please, educate yourself about domestic violence/abuse at the following sites, and step back, take a look at your relationship with this man, and be brutally honest with your Self about what you've observed in the past.

www.heartlessbitches.com
www.stoptheviolence.org
www.mayoclinic.com/domesticviolence
www.ndvh.org
www.ncadv.org
www.usda.gov
www.dvguide.com

As you can see, ConfusedFriend87, there are many, many sources of information with regard to domestic violence and abuse because it is at epidemic proportions and getting worse, every day.  Those who are "friends" of the perpetrators are just as abused as the primary victims because they are ALSO being used in one form or another.  You cannot save this person - only he can change his choices of actions and alter his Life's Path.  You are not responsible for this person's choices - regardless of what he may say or accuse you of, only he is ultimately responsible for his attempted suicides.  My ex used to threaten me with suicide on a routine basis in front of our children.  Always, it was my fault that he would arrive at his decision and always, ALWAYS I would do whatever he asked (demanded) in order to prevent him from shooting me, our children, and then himself.  Without going into a long, drawn-out recollection, he finally stopped using that ploy when I demanded that he either shit or get off the pot where his threats were concerned.

You are not safe with this person being a "friend."  You may need to step back, take a good long look at why you're insisting upon being associated with someone who is a perpetrator of violence, and (perhaps) begin making some changes in your own life so that you can choose friends and associates who will not be a danger to your health and emotional well-being. 

Finally, pity the "crazy bitch" that has endured his violence.  You do not have ANY IDEA of what really happened between them because he hasn't been truthful or honest about his actions, from the beginning.  His version of events will always (and, forever) paint him to have been driven to perpetrating violence because of something that SHE did to deserve it. 

Best wishes to you.