I'm a little concerned... Period issue:

So I started taking birth control pills like 3 weeks ago, and I took them on time and never missed any. I expected to see my period still since it was my first time taking it. My period came on 4 days later than what it usually does. At first it was light and then after a couple of days it started to get really heavy like crime scene heavy and I had bad cramps constantly. Usually I would have the cramps in the beginning along with the heaviness but it flipped. Today will now mark the 10th day my period has been on and I'm a little concerned... Usually my periods last 4-5 days not 10. Never 10! And what's even crazier is the clots that im getting they are still huge, and I still have cramps... Should I go see my doctor? Is this all because of the birth control? I heard that starting to take the birth control can throw some stuff off but I didn't think this much... I'm sorry if this was too much. Any help is appreciated ♡