Late period

So my period was supposed to start on Saturday, the 25th. My periods aren't super regular, and they usually come a day late if anything. I'm now 2 days late, which isn't really normal for me. Within the past month I've had a big schedule change (school ended, so my sleep schedule is different and I don't get out a lot), and I've traveled to a few different places. The only catch is that on Saturday, the day I was supposed to start my period, my boyfriend and I were fooling around and he entered me for like 3 seconds. I think a little bit of pre cum was outside of me, but it didn't really go inside. Please don't make fun of me, I know it was stupid. Please just tell me, do you think it's more likely that I'm pregnant, or my body is just thrown off from the past month?