Found condom in me.....

So I just had an amazing sexfest with my partner. We have had sex a few times now but nothing like this. This was hours of finding each other's spots and likes and just exploring each other's bodies. All well and good we changed condoms if one came off or was used. Over 24 hours later I was changing and felt something. A condom was half falling out...... It was 12 am so to late for local store to be open and plus it was already past time to take morning after pill. Should I be scared I'm 7 days away from period, says I'm only 2.7% likely to get pregnant but either way I'm a single mom of a 9 year old and his daughter is 19... We don't want kids. I'm scared to death to even tell him. I don't want to ruin this. Any words of wisdom??