Hello, I May Be Pregnant But I Am Unsure. It

Hello,

I may be pregnant but I am unsure. It has only been three days since...I did take the Plan B pill 72 hours after (which i'm aware should have been sooner). I have cramps and diarrhea. Although, yesterday for the first time, I had a Monster Protein Energy that made me feel very sick. It was loaded with caffeine (165 mg) which i am not used to. I was jittery, nauseous, and I got diarrhea. I also am slightly lactose intolerant so it had many milks in it. I know I definitely got sick from the drink, but I am not sure about pregnancy.. I am unsure if it is both or if it is just a bad time to get sick right after sexual activity..