No AF, yet confused!

Cristen
Today makes AF three days late and still no signs of her coming. I have taken three different pregnancy tests, all three have came back negative. Usually my boobs are pretty sore to the touch and they actually are not that sore as usual. My period is always on time and never late so it's kind of confusing. Last night I noticed when I went to pick up take out for dinner the smells kind of made me nauseated, which it never has any other time I've been in the restaurant. Even after eating breakfast this morning I felt kind of nauseated but didn't throw up. Could I be pregnant even though all three tests have been negative. I'm praying this is my month!