Should I have NOT taken Plan B?

This is going to sound really messy, but bear with me. On May 26th my SO and I had sex. It wasn't the first time. I had also ended my period a few days earlier. We used a condom, but it broke inside of me without either of us noticing. He pulled out before he came though, and after when we were cleaning up, he told me he noticed that the condom split in half (later I found the other half after I peed when I wiped). He insisted that I should take plan B just in case, EVEN THOUGH he came outside of me AND the tip of the condom was still inside of me. I took the pill 1 hour after. Two weeks later I'm bleeding super badly and I feel like shit. Although it's too late now, was taking the Plan B unnecessary? And what does this mean for my health?