I’m currently 4 weeks 3 days...

From the 3rd day after conceiving until today my uterus was feeling so heavy and a little pressure/crampy like my period was coming. My doctor assured me that’s very normal. Well today all uterus pain is gone. Should I be worried? My boobs started hurting like hell today so I’m taking that as a good sign but I’m a little worried about why my uterus suddenly stopped hurting. Also, I’m officially 4 days late. Any advice is appreciated!