1st month on the pill

I started taking my birth control on a Sunday but on the Sunday of week 3(active pills) I started a very light period which didn't concern me bc I know birth control can do that sometimes however it is Tuesday of week 4(sugar pills) and I am still bleeding. The first few days where light but now it's like a normal period w an overall time frame of 1 week and 2 days but my normal period last 3-5 days. Should I be worried & how much longer will this last?