Labor after sex

How quickly after DTD did you go into labor towards the end? I’m 38 weeks 4 days today and tbh this is the first time we’ve participated in several months, I was too uncomfortable to do anything and we couldn’t find any positions we both enjoyed so we just took a break until this morning lol this was around 10am. Ever since I have been experiencing lots of cramping and increased uncomfortably all day long and now it’s been going into my back too and down my legs. I’ve tried drinking water and propping my feet up and nothing seems to be alleviating the pain. It does seem like it’s coming in waves but not consistently spaced and then other times it’s pretty much nonstop. Baby is super active, probably even more than usual so I feel good there but could this possibly be labor or is this just normal after doing it so late in the term? Like I said I have nothing to base it off of the last time we DTD was in December so it was a very different ball game lol

Editing to add I haven’t had any bleeding or water breaking and as far as I can tell I haven’t lost my mucus plug. I actually had a baby appt this morning prior too and she did a cervical check which I know can change quickly but i was only 1 cm and 20% effaced.