Braxton hicks? Are you staying plenty hydrated? You can mention it to your dr at your next appt but it doesn't really sound worrisome if there isn't any bleeding.
ETA: if it starts getting the worse and you feel like they could be contractions, I'd call your Ob and get checked out.
Re: Mild cramps
ETA: if it starts getting the worse and you feel like they could be contractions, I'd call your Ob and get checked out.