Advice needed: Should I tell his ex girlfriend?

Chelsea
Hi everyone. I dated a guy when I was 19 for 8 months and then he broke up with me. I was a virgin when I met him and was with only him exclusively when we were dating. During our relationship I found out I contracted herpes from him. I told him what the doctors results were etc and was not blaming him at all. In fact I kept saying WE will get through this etc. he was not comforting or supportive and ended up putting his hands on me that night because he was so mad. I told him he needs to go to the doctor and get checked out (especially because he had an open breakout on his penis at the time) he never went.
Fast forward to now. I am 25 and a mom to a beautiful 9 month old little girl. I took caution during my pregnancy and giving birth because I was mindful that I have herpes and it is dormant in my body. (You will forever have herpes if you get it once. You might not have a breakout but it doesn't mean it's not there anymore. There's no cure.) I had a c-section because of the risks of my daughter contracting herpes from my birth canal. Any risk was enough for me to ask for a c-section to make sure my baby was safe.
I have recently come in contact with my ex's mom. Just small talk. But she told me that her son (my ex) broke up with his girlfriend that he had after me. 
I need advice because I battle trying to get in touch with her. I want to tell her about what happened to me only because our boyfriend was in denial about giving me herpes and acted like if he doesn't think about it and acknowledge it, it will go away. I'm scared for the girl if she may have it and doesn't know she does. She is now with someone else and that means if she doesn't know she has it, she could unknowingly pass it to her new boyfriend, other partners in the future, AND she could put her future children in danger if she delivers them naturally. I just feel like I would want someone to tell me. I look at my daughter and wonder if I didn't know I had it, would she have gotten it if I delivered vaginally? I would have felt so heartbroken because this little life shouldn't get it if it can be prevented. What would you do? If my ex accepted the fact that he gave me herpes/he has it, got medical help and was conscious of breakouts and sex, then I wouldn't worry. But because he was in so much denial and didn't admit he had it, it scares me for anyone else he comes in contact with. And because I have his (now ex) girlfriends information, I don't know if I should contact her and ask to meet with her. Any advice is appreciated. Thanks