Tested positive for syphilis 15 weeks pregnant

Hi so I am currently 15 weeks and I came back positive with syphilis and don’t know what to do I’m just so worried. My last syphilis test was at my first prenatal appointment at 7 weeks and I tested negative. I haven’t been with anybody since October and it is currently end of December so it’s about to be 3 months and the last person I had intercourse with was my baby’s father. He swears he got tested last month and tested negative for it but I don’t believe him since he was cheating on me our whole relationship with multiple people and I didn’t find out until after I had broken up with him. I went to the doctor office the day after Christmas (yesterday) because I had almost passed out at home and they ran multiple test on me then I got a call from my doctors office today telling me I texted positive on the (Treponema Pallidum Ab Screen I) test and the RPR test also came back positive with a 1:64 titer. I rushed to the ER in tears and got my penicillin shot they said since they caught it so early I don’t have to come back in for the two other shots but do have to follow up with my doctor and a doctor who specializes in syphilis. I told my baby’s father and he swears he doesn’t have it and that and I quote “if I had it I would’ve told you and not put our daughter at risk”. I’m getting on here to ask if this has happened to any other mamas out there and has your baby been delivered safely and without complications I really hope my daughter is going to be okay I don’t even care about myself so if you have any answers please respond.