Had unprotected sex on 3rd, 4th, 5th and 6th day of my period..is there a chance of being pregnant?

Unlikely: For women who have regular, predictible periods, having unprotected intercourse on days 3-6 of their cycle would not result in achieving pregnancy. However, women with irregular cycles and/or bleeding, should not feel confident with unprotected sex, due to irregular ovulation; the possibility is greater that she could conceive.

If it was really: Your period u should not be ovualting but, u should be using protection at all times.