Did he cheat?

I apologize for the long post.
My husband and I have been "together" exclusively for 7 years going on 8. We haven't talked about our sexual history because he didn't want to hear about my past but I knew that I was his first girlfriend. I only had two sexual partners in the past before him; both were one time occurrences, one was oral the other was anal. Both I regret. Anyways, I was young and stupid, didn't use protection but I did get my Pap smears and STD/STI testing every 6 months. They came back clear everytime. My husband and I got married a year after we started dating then we had to be apart for one year so I could finish school and he could continue working to support us. I had my first baby 9 months after we got married, I kept getting tested everything was clear and I was healthy. Then we were finally living together again after I graduated, he seemed completely different was not at all sympathetic, avoiding me etc... we had another baby a year later. I started getting sick, had placenta accreta, needed my tonsils removed then 9 months after I gave birth to baby #2 my STD test came back positive for chlamidya. I was in shock, this whole time everything came back okay. He took his antibiotics and I took mine it was the 3 day pack, I told him it was for yeast infection because I didn't want to tell him about my past since he didn't want to know but in the back of my mind I've been doubting him this whole time since I was faithful. So my question is, could this STD be because of my past two partners? How probable is it that chlamydia lays dormant throughout one entire pregnancy and comes out 5 years later? If it was in me the whole time what are the health repercussions for my kids? While we were apart he went to jail twice for a DUI. It's been almost 4 years since I tested positive for Chlamidya and didn't tell anyone but it's still bothering me and I don't know if he would tell me the truth even if I asked because he knows that we would be over.