problem after mc and ectopic pregnancy

i had mc last year june then again i got pregnant in july but this time it was ectopic one and for the 8 weeks we coultnt understand the prb as my ultrasound shows nothing. HCG levels were very low but proceeding. both time i have started bleeding at 13 days late AF :( finally on sep 4th 2014 i got my first methotrxate shot then within 2 weeks my hcg level were back to 0. The prb is i cant feel completely normal after that my abdomen hurts when i work too much or stand. in nov 2014 i feel normal as before but on fwb 3rd i used WC for pee and its been 8 months now i cant feel normal and healthy :( cant do too much work. all my u/s is normal.