Did you have a period in early pregnancy?

Well if I am pregnant I probably would of conceived on Jan. 20. Me and my boyfriend had unprotected (pull out method) on Jan. 20...but I did get my period on Feb. 4th, but my period lasted about 8 days and it was really really light, different than other periods. But today I noticed that my stomach feels like it's full ( only ate raisin bran and milk), and I feel like throwing up. Did anyone experience this? or did you get a period in early pregnancy?