Could I Be Pregnant? Is It Too Soon To Tell?

my symptoms are nausea, vomiting, headache, dizziness, fatigue, weird appetite, warm all the time but no fever, back pain, sensitive to smell, breast tenderness, and frequent urination. i thought it was the flu but the nausea and vomiting come in waves but mostly in the morning and at night. also, i had a misscarriage on 6/8/11 but and had sex on 6/11 and 6/15. and my periods are irregular. when should i take a pregnancy test?