3 Days until AF .... and I think I'm pregnant.

I ovulated on the 21st, the day after I had cramps and felt nauseated. Since then I get nauseated have dry lips, have REALLY bad gas, and sometimes off and in cramping. I took a test last night that looked like it was going to say positive but said negative. And this morning I took a test that was negative. Is it to early to take a test. ? Do I need to take one after a missed period. ?