A possibility?

Is it possible to get pregnant a day before your period starts even when using protection during sex? I’ve been having symptoms like fatigue and tingling in the stomach for example but I’m either paranoid, stressed or really pregnant. I know it’s a silly question but I’ve been on edge and my next period doesn’t start until 2 weeks. Also I do have problems with endometriosis and ovarian cysts and made an appointment just in case. This is like the longest month of my life 😅