should I be worried ?

Mayra
Okay , so I had unprotected sex Sunday& Monday . I took the plan b Monday after I had sex. Then on Tuesday I had unprotected sex again but he didn't get to cum . He stopping in between because he didn't want to cum yet. & well at the end we could finish because we had to leave. The app says I'm suppose to get my period in 12days. But I am cramping and I feel like I start my period and then I go check and I haven't. Shoul I be worried about me being pregnant? That's all I think about . He said we should be good but I'm honestly freaking my self out.