I’m a complete emotional wreck! I’m so depressed that I know I’m hurting my baby and I don’t mean too 😢

A little personal information about me and why I’ve been so completely broken is because my boyfriend and I broke up September 14th 2018 and got back together October 13th 2018 a whole month later. Well within that month it’s true that I was with one other person October 11th 2018. I was with my boyfriend constantly from the 13th and on, little sex for about a week straight or more every night.. about maybe 2 weeks ago I found out that this baby MIGHT not be my boyfriends considering I slept with someone two nights prior to being back with him AND FAITHFUL and I made sure to tell him as soon as I found out.. there is no doubt in my mind that this baby isnt his because the other guy and I used protection but he now claims to not have and my boyfriend was aware of this and was even okay with it but now since he broke up with me yesterday that’s what he’s telling everyone and I know it hurts him I get it, I put myself in his shoes.. he’s not the bad guy here no one is I wasn’t with him when this happened obviously I would never cheat on him. I love him so much and I just want everything to go back to the way it was my whole life has changed since he’s left me yesterday and all because of me not knowing who the father is but I’ve looked up on almost every <a href="https://play.google.com/store/apps/details?id=com.glow.android">ovulation tracker</a> and I don’t know how to read them so someone please please help me do you know who my babies father is?