My Period Ended On Feb. 9th - Last Week When

My period ended on Feb. 9th - last week when it was suppose to come I was spotting for five days but never a full period. It's now March 12th and I have not had my period. I have bent akin some yoga classes which made my abs sore - but I was diagnosed with a sinus infection on Thursday. The abdomen pain has been getting much worse and I am getting nauseous and week. I am not sure if the abdomen and nausea could be from the coughing and the antibiotics. But I know my body pretty well and I don't feel right.