What do early contractions feel like?

I'm 38+5, FTM, and just wondering what early contractions feel like? I've had what feels like mild period pain on and off for the last two days, and have a tiny amount of blood in my underwear (haven't had any bleeding at all before). I've had braxton hicks since second trimester and have always been able to feel the 'contractions' from that but this feels slightly different. Could this be it?? Or do braxton hicks just get stronger as you get closer to due date?