Take plan b or not?

Okay so I did something I shouldn't have done - have unprotected sex sunday morning and then monday morning(today) i get my period. I'm only just curious if I should take the plan B or not. Could i still attain pregnant if I don't take it?
Answers:

I'm confused n troubled!?

when you enjoy unprotected sex even if its on your period you hold a chance of getting pregnant. if you are going to be doing this and be adjectives worried and stressed out every time then take on birth control. my friend did it with her length and recently have an abortion...so be careful

I know this is gross but i entail to know why..?

Call your Dr. or Planned Parenthood and ask your question.
Please be wary.

Mirena questions?

well usually, you won't enjoy any chances of getting pregnant since you enjoy your period very soon. Plan B wouldn't be necessary and it could affect your system of reproduction soo try to avoid them unless near is emergency. The period is already a sign that you aren't. But do try a pregnancy interview instead. Clear Blue is the best but I am sure there are also other brand. dawdle like a week after your time of year or so to test it.
Goodluck