Is it possible i could be pregnant? my boyfriend's penis by my clitoris and released precum. he did not ejaculate. i have pcos; missed birth control

Possible: It's always a possibility. If you are a week late, take a home pregnancy test. If it's negative, repeat in a week.

Yes: It is possible but really not likely. If yo do not want to be pregnant you should consider some form of contraception, even with your pcos.

Possible unlikely: Sure there could be enough sperm there to lead to a pregnancy. But given that your periods are likely irregular from pcos and you likely were not ovulating, the overall chance is very low but not zero.