Hey! There is a chance that you can be pregnant. The thing is, the symptoms for pregnancy and PMS are a lot alike. Swollen breasts and mood swings are common during pregnancy and right before the start of your period. If you’re in doubt, wait for a couple of days and see if your period comes on. I know it might sound hard, but try not to stress because that can sometimes make your period a little late. If it doesn’t come on, then you should go ahead and take a pregnancy test. Let us know what happens. Good luck to you!