HEARTBROKEN :(

I'm 33 years old and my bf is 27. He has a 6 year old. I was pregnant 5 years ago this month by a different guy but lost the baby. I've been with my bf for over 3 years and we don't use protection nor am I on the pill. I started to worry last year so I had us both get tested. long story short I was good to go with getting pregnant, it was him! his sperm count was extremely low and they weren't fast swimmers either. the Dr said he couldn't even produce enough for <a href="https://glowing.com/glow-fertility-program">ivf</a>. she recommended a specialist to him but hes been in total denial ever since and thinks it still me. well last month I found out he has been cheating with me. this woman claims she is pregnant with HIS baby!!! is this seriously possible I mean I saw and heard wlth own eyes and ears he would meed a specialist. I'm so sick over this bc I do love him and wanted us to have a family. he's still living here and wont admit he has this girl pregnant but I've seen his convos with her and she says its his.