Labour stopping

I’m currently 40+5 and this morning I think I started having contractions. They weren’t as bad as I’d expected (more like severe period pain). I started timing them and for 2 hours they were around 20 minutes apart so I was pretty sure this must be early labour. Everything has totally stopped now. I haven’t had any pains or discomfort for around 40 minutes. I’m not sure if the whole thing was just in my head and I was just having some normal cramps which I’ve been having occasionally for a couple of weeks or if this is the start of labour. Can things just stop?