Hey.. I Missed My Periods. Last Time It Came On

Hey.. i missed my periods. last time it came on 18th april.. my period cycle is normal. (28 days).. today is 28th may, and i dont have my peiods yet. i had unprotected sex on 27th april like for 1 time, otherwise we used protection. he pulled out before sperm discharge. but for surity i had unwanted 200 mg tablet. but till now i dont have my periods. and there is no source to check whether pregnancy is positive or not. i have unwanted kit with me. can i take it? what will be the consequences of that if i am not pregnant. knowing my situation, can you tell me whether there is a chance of pregnancy or not. or is the delay because of that unwanted tablet i took.