Spotting for weeks

Has anyone else experienced spotting for weeks during early pregnancy? It started at 4 weeks and now I am 6w1d. My hcg numbers are more than doubling and a gestational sac and yolk sac were seen at 5w2d. Going on Wednesday to see if we can see the heartbeat. This is my third pregnancy and I have never had this happen before. Spotting is brown and pink and only when I wipe. Sometimes I go days without anything and others it's all day. Agh!! Feeling super confused.