anytime you have sex there is the chance of getting pregnant, im sure you know that.
now would not be too early to take a pregnancy test or go right to the doctors. its been three months of having unprotected sex and im assuming your boyfriend has finished inside you as well for what you have wrote.
you are never going to know if you are pregnant or not by just guessing, so there are two things you can do, take a pregnancy test, or go and see your doctor and ask him or her to do a blood test to find out if you are pregnant or not.
not all women get the common pregnancy symptoms of morning sickness, every pregnant woman is different.
so i would suggest doing one or the other or both soon. use the pregnancy test as instructed, with the first morning urine.
and see your doctor.
if your not pregnant, i would suggest for you to get on some birth control to avoid a situation like this as well. or tell the person you are having sex with to wear a condom.