advice would be helpful. 😊

so I had unprotected sex on April 30, my peak day. I got my period may 15, or what I thought to be a period, it was only 2 days.. definitely over by the 3rd day. was more so of a brown color, than bright red. not much cramping. so I wasn't concerned.. at all. until about a week ago when my breasts became very tender, and now I'm beginning to lose my appetite, and feel nauseous after eating. could I be pregnant? and my cycle length is 34 days.. & my period is due the 20th.