Plan B

So last month I had a scare with the whole pregnancy situation and decided to take a plan b.

(I had sex with the condom but we ended up taking it of for about two minutes and put another back on about twenty minutes before he finished)

I ended up bleeding for about ten days like three days later.

It's been a little over a month and now I'm about four days late for my period, is that something I shouldn't be worried about?