is this normal???

Okay I came off my period on the 2nd of feb, had sex on the 3rd (Friday) and the condom split! I couldn't get the morning after pill untill the 6th (Monday) spoke to my doctor on the Monday an he said I'll be fine to take it as it's within time frame...
Now yesterday I started getting my normal period symptoms, really bad migraine that no tablets or sleep will get rid off and bad period pain, wake up today to my period?
Sorry if this is TMI!
But it's not as heavy as I normally am and it's dark red/brown, it's normally red?
I'm not suppose to start for another 2 and a half weeks? I'm really regular!? 
Is this normal? After taking the morning after pill?