Help...

I had a period on my birthday 28th of April. I remember me and boyfriend had sex on my last day of ovulation. That was April 15th. Now when my period came i didn't know that it came i had no PMS symptoms.. AF went off in three days, after those three days my nipples where a little sore.. My areolios are a tad bit bigger and darker, my appetite picked up a little, I've been a little more tired and noticed i have some nauseous moments.. So im wondering if im just trippin or an i having early pregnancy symptoms. My next AF isn't due till June 1st.