Salam! Cramping lepas relations tu memang boleh jadi normal terutama bila baby makin besar, tapi since yours getting stronger sekarang better check dengan doctor just to be sure everything's okay, a few of my mum friends had the same and their OB said it's ligament stretching, tapi some cases kena monitor closely lah. The fact it goes away the next day is a good sign, but don't wait, especially if it's getting more intense, just mention it at your next antenatal checkup or call your clinic. First pregnancy memang ada unexpected sensations kan, so better safe than sorry!