What are the possibilites of me being pregnant?

So, I had PROTECTED sex last saturday (condom-Durex extra safe), my boyfriend didnt finish inside me as he pulled off a while BEFORE he finished. On Tuesday I am supposed to expect a period. My boobs have started to get harder and the bottom of my belly started getting harder too and looks more bloated (this happens to me everytime im gonna go on a period but this time my boobs arent that hard as they were other times, and my belly seems MORE bloated than other times and I want food all the time) Do u know if there is a chance of me being pregnant? Or its just PMS?! t h an k s