I Had Unprotected Sex 4 Days Before My Period Is Due. I Didn't Use Condoms And I Never Took Any Pills. Is There A Chance That I Can Get Pregnant?

Actually....it depends on when you ovulate.  I got pregnant 1 day before I should have started my period.  I know, I know....nobody believes that!  But my husband was out of town that whole month and that is the ONLY time we had sex, and I was pregnant!  Here's how it went, my 1st day of my last period was May 1st of that year and conceived on May 31st.  Perfectly healthy baby girl!

My last period was March 21st-24..And me and my boyfriend has unprotected sex on April 17th and I start my period on the 21st I have a regular period every month I have been feelin alittle weird and I my breasts are alittle sore I havent felt this way since I first went through puberty. How likely is it that I could be pregnant and is it even possible to get pregnant days before you period?
Thans for any advice you give me.

If you think that you will get pregnant then you can easily abort your unwanted pregnancy using cheap abortion kit online. This kit is easily available online. So do not worry if you get pregnant.

Logically it is not possible to get pregnancy 4 days before the periods. Because the ovulation takes place in the middle of cycle under normal conditions but exceptions are always there. I advise you to wait for periods and if missed on due date then get pregnancy test.