Pains and bleeding

I've recently found out im pregnant, im around 4 weeks pregnant, ive been having stomach and back pains for around 1-2 weeks now and feeling nauseas for around 5 days. over the past 2 days the stomach pains have gone to a stabbing pain and I was told this was fine as it was stretching pains, today I have statted to bleed a light pink discharge, i am only bleeding a little however I don't know what I should do.