I might be pregnant,

I have a very regular cycle, my period was suppose to start on July 9th and it didn't come. I have mild period cramps which is odd because mine are always very painful. Here lately I've been getting the random urge to vomit without nausea, and my lower back hurts! Two weeks ago I had a yeast infection and I found two or three drops of blood in my panties two days in a row? Could I be pregnant? Help!!