I had it from 30 weeks on with my twins
and I don;t remember with my singleton (sounds about similar to your timeframes)
with the twins I called docs because they would progress to 4 minutes apart through the night - but by AM they were better - it was weird - I got ready for the hospital at least 3 times because they got so close together
then when it was real I didn;t take it seriously because of all the times it wasn't!
I would call your doc and ask -
I had them like that too, but I would call your Dr. since it's still so early, especially if you were dialating that early on with your first. My Dr. watched them, but I didn't get the pain in the butt, sorry for the wording, till the very end. Good luck, drink lots of water too, may be a sign that you need more.