Pregnant?

Can you get pregnant from precum? He used the pull out method...had sex the 22nd and the first day of my last period was the 15th and now I just feel off. Last night I had slight cramping in my lower right side of my stomach and a shooting lightneing feeling that lasted a few seconds in the center of my stomach from my belly button down. Ive been extremely tired and hungry but having a lot of heartburn and nauseous at the same time. I have been having weird irregular periods that I bleed mid cycle so I don't know how to track them. My doctor said that could be ovulation?