Pain in lower abdomen

Hi hun. Around 4 or 5 weeks, cramping could be a sign the embryo has implanted nicely into the lining of your uterus. Or it could be a sign your uterus is expanding and stretching your ligaments.  If you are having any kind of vaginal bleeding along with the cramping in early pregnancy, you should call your Obgyn and they should be able to order hcg or an ultrasound to figure out what's going on. Hope this helps. Hugs!