Hi, I'm A 22 Year Old Girl And Have Had

Hi, I'm a 22 year old girl and have had a constant period since around May time (6 months) with breaks of only 1 or 2 days max. I went to my doctor in June about this and she suggested I get a smear test. They were unable to see anything because I was still bleeding at the time of the test. I have the implant and have always had "normal" periods until this. Should I be worried? What could be the cause?