Hello i had unprotected sex with my partner yesterday and he conceived in me and i start ovulating today can i become pregnant?

Yes: Unprotected sex is best way to get pregnant, especially if timed around ovulation. If trying to conceive, start taking prenatal vitamins immediately. If not, then check out http://www.plannedparenthood.org/all-access/my-method to research best birth control for you. Then discuss options w/your Family Doc. Consider using condoms each time to lower risk of sexually transmitted infections/diseases.