The morning after pill is a form of emergency contraception
that is taken, as in your case, after an episode of unprotected sex to prevent an unwanted pregnancy. The morning after pill works specifically by preventing ovulation - the release of the egg from the ovary. The pill is well tolerated by most women, and it is quite effective at preventing pregnancy.
In order to be most effective, the pill needs to be taken within five days of having unprotected sex. Since you took the pill only two days after having sex, the chances are very high that the pill should work for you. Regardless, I recommend that you discuss the matter with your OBGYN.
In a small percentage of cases, the morning after pill does not prevent pregnancy. Also the morning after pill does not have any function in preventing the spread of sexually transmitted infections. Therefore, if you do not have a menstrual period, or if you have other signs of potential pregnancy you will need to see your doctor
. Also, it is a good idea to go see your primary care doctor
regardless if there is any concern about the potential for sexually transmitted infections, which is something that they will be easily able to screen you for.