3 days late

So I was suppose to start my period on the 20th and it is still not here, I took a test on the 21st which came back negative. Also on the 21st I was having this really weird pain down below. It felt similar to becoming raw from sex, but different was dull and achy to. I haven't got any for like 3 days now. I am 30 years old and it was the first time I have felt this way really it was different than anything I've felt before. Currently I am having some side pain. and the past few days I have been so terrible tired. I have recently moved across the country and I'm not sure if my body is just trying to get used to the move.