He gave me a plan b after we planned a baby

So last night we did the deed because I was at my peak. We were hoping it would be a sticky bean. After countless miscarriages I was so hopeful. This morning he came in with a Walgreens bag and I opened it. It was a box ... PLAN B. He told me I should take it because he now doesn’t want to stick around. Then he told me he had to tell me something. That he wanted to be honest and been seeing someone else and she’s possibly pregnant. I’m so crushed. I want to take this pill but my heart is telling me this could be my miracle baby. I’m crushed. The cheating.. him throwing me a box of plan b. 🥺🥺