Infidelity

So my husband and i have been together for 7 years and yes we’ve had our ups and downs. This year has definitely been the hardest relationship wise. I thought we were ok I thought we were happy. In August my husband went on a mission in Alaska for a couple weeks I was about 32 weeks pregnant, well it turns out he slept with another woman the last night he was there. I forgave him and we’re currently trying to work it out but as of a few days ago I went through the phone records and it turns out he’s been talking with her these past couple of weeks. I have forgiven him for now I don’t want to lose him because I love him so much but I can’t help but feel so stupid and used. I’m not sure what to do. Do I continue and fight for our relationship and for the sake of our baby or do I just drop it?