7dpo please help

Meme

I'm just curious!

Period came January 27th lasted until February 2nd

We did the DO February 6th and 7th but I had taken the plan b (DON'T JUDGE) BUT now I'm feeling so weird been very exhausted more then lately, extremely nauseous,nipples are so sore, urinating alot ,and slight cramping and a irritating throat , went to the ER LAST night pregnancy test was negative .

Could this be the plan b or what I just feel so wierd?????