Sex and painful contractions

My husband and I had sex for the first time in a while last night. Almost immediately after I had painful contractions that I actually had to work through a little. It reminded me of when I was in labor with my first. I'm still having them the next morning 😣 though they aren't as painful now. I knew semen could cause contractions, but sheesh this hurt! I'm assuming this isn't actual labor since I was able to get through the night and they aren't as bad now, but is anyone in the same boat after?