Plan B Pill?¿

So.... long story short... condom broke and my boyfriend thought he came in me, so he bought the plan B pill and I took it. This all happened a few days before spring break. So during spring break my period started and It ended that Sunday so it was a full week (like normal) I figured it was finished so obviously I stopped wearing tampons. A couple days later I was spotting blood in my undrware. I figured it was just a little extra so I didn't really think anything of it. Went to school the week after that and more blood started coming but it was A LOT! My bf keeps tampons in his car for me so he got me one during school and it's been 4 days since this has happened and it's still coming out heavy. Should I wait it out or see my doctor?