Feels like I ran a marathon?

Kaitlyn
I used to have very odd period pain. Rather than being in my abdomen, my legs always felt like I just got done running a marathon. Only from the knee up. 
Up until yesterday, I had a pulling feeling in my stomach that felt like I did crunches. When I woke up today, it was gone but my legs have the same pain they do when I have my period. I'm worried and not sure if I should be. Has anybody else experienced this? I'm 5 weeks.