I had my last period on 14th February.I took a home pregnancy test on 17th march and blood test on 19th march. Both came negative. I recently started exercises three days a week. I also took some antibiotics just before my period was due. Now I am 7 days late. I have some mild cramps only, no other symptoms. Is the exercises and the antibiotics making my period late or am I pregnant? Or did I test too early?