No period and nervous!

Marisa
I haven't had a period since June 11th and I'm a little nervous. This has happened to me in the past..about 2 years ago, but that was when I first got off my birth control. I took two pregnancy tests, one after I missed my period last month and another about two weeks after that...both negative. Idk what could be wrong. Wondering if anyone has been through this and has some insight on what the problem could be.