What Causes Morning Sickness,mild Fever,vertigo And Delay In Periods?

Dear doctor, I 29 F, detected with hypothyroidism last year, Since that time i am under medication with Thyronorm, with regular chek-ups. My periods are also quite regular. This month I missed my period and had mild fever, vertigo, chills i suspected for TSH level elevation and TSH test reveled normal levels of TSH (7 days after my period due date). Then I went to gynic she screened for pregnancy with urine kit, it was negative. She asked me to wait for 10 more days. I was feeling all the pregnancy symptoms like morning sickness etc. But suddenly on 12 th day I had my period. Even I checked on that for pregnancy by kit method, it was negative. I am not knowing what was reason for all these symptoms though I have normal TSH levels. Please give us suggestion thanks Pallavi