AF is way late, but Negative test?

My boyfriend and I have had sex at least once or twice every week this month and now AF was supposed to be here on the 25th. Well it's the 30th and my boobs are so sore I could cry, not to mention my nipples just started becoming itchy as well as super sensitive. However I just tested and got a BFN. I didn't use my morning urine but would it make that big of a difference? Also, the test is a dollar store test. Any advice is appreciated!