I had sex 3 weeks ago and i had my last period around the 28th of feb to around the 3rd of march. And i havnt gotten this months.. my boobs are really sore, i feel sick , my belly is really sore and im getting soreheads. I thought i was pregnant so i took a test this morning and it came back that i wasnt pregnant. And i had a spot of blood in my pants but not my period this morning to could i have took the test to soon or what why havnt i took my periods?