bleeding in pregnancy is never classed as normal BUT often there is no cause for concern. go to the doctors tomorrow and tell them and they will probably have you in for an early scan when you are 6 weeks.
lots of people bleed in early pregnancy and everything turns out alright. i started spotting brown blood last october at 5 weeks, which after a few days turned red, and i had an mc BUT, like i said, it doesnt alwasy mean bad news.