Implantation bleeding? day and a half later she took plan b

Hi,

So my girlfriend and I had unprotected sex around the time she would be ovulating (march 23). I pulled out but it was still incredibly dumb. A day and a half later she took plan b one step. Now she has what has been seeming to be a period even though it would be a week early (her sister's is now so maybe syncing?) Anyways, she has been feeling the last couple days like she is about to have her period, kind of moody, and a breakout (her normal signs before). So then last night she started what I thought was her period, it flows like normal, is red like normal, and is acting as if it is completely normal. Then this morning the bleeding stops, she is still feel the same way like she always does during her period. So then it decides to start again and is still flowing like normal and looks normal, except her normal period isnt for another week. So would this be considered implantation bleeding? She said she doesn't feel pregnant has nothing else? It just seems like a normal early period that stopped and started. Any insight would be appreciated.

Thanks