I had sex and the condom broke. The morning I woke up, it seemed like I started my period. A few hours later, I took an emergency contraception pill, and as I went about my day, I noticed that my "period" stopped. Where did the bleeding come from? Was that my body reacting to the extra hormones from the pill?

No idea, and the morning after pill is not 100 percent effective. The pill as many side effects, some women have none of them, others all of them

You are just going to have to wait, and see if you have your next period or not. If no, wait about two weeks after you miss you period and do a test