What do early contractions feel like???

hi ladies, I'm 38+4 and this is my third pregnancy. my first two.... my waters broke before contractions began so I never had to question what was going on. the last few hours, I have a period type lower tummy cramps that is there constantly.... accompanied by the feeling that I need to go to the toilet! periodically this constant cramp intensifies but only slightly at the same time my stomach is going hard. I'm rested and hydrated. I've also experience this a couple of times in the last couple of days and I'm so fed up of trying to guess whether it's braxton hicks or pre labour. I obviously know that once real active labour is on the way then I'll definately know the difference.... but what do those first few early contractions feel like????