7 weeks pp and still spotting?

so here's the full story;

I bled for the first 6 1/2 weeks, stayed red and heavyish and ended up calling my OB because I started bleeding super heavy again(around 5 1/2 weeks) and I was worried that something was wrong.

OB stated that it must be my period because I'm both breast and bottle feeding but since it was so heavy she prescribed me Methergine to stop the bleeding.

it was 6 pills over a 2 day period, it ended up slowing down and after a fee days stopped.

it stopped for 3-4 days and now I'm back to spotting red again and it seems to be getting heavier like I'm starting my period and this time I'm having cramps.

should I be worried?