What Are The Early Signs And Symptoms Of Pregnancy?

Hello. I m curious or not as to if i m pregnant. My boyfriend and I did not have sex (he was not wearing a condom), but he did cum and I m afraid that it managed to get inside. Immediately after I took the morning after pill. This was four days ago and I m experiencing dramatic mood swings, cramping, fatigue, dizziness, and food cravings. This is my first time with--well, with everything honestly. We did have unprotected sex once before, but we realized what we were doing and he pulled out moments after without ejaculating. That was 3 days before what I previously told you about. I m 17 and very underweight at approximately 86 pounds. Moments ago, I thought I got my period (it was very light and light in color), but found it it may be implantation bleeding? I definitely feel as if I m on or about to get my period. Though, I m scared because these could all be symptoms of pregnancy as well. What do you think?