Symptoms of being pregnant, no preiod, and neeed help please?

last month i missed 4 of my birthcontrol pills..the dark blue ones i think and so i just threw the pack out because i figured it was useless after that. I did have have sex with my boyfriend even though i knew it was unprotected...so for the rest of that month i did NOT have any birth control pills.. about a week before my period was due i had brown discharge that was on and off for about 2 days..not even enough for a pad and i had severe cramping, headaches, nausea ,and i feel bloated. So i took 2 Walgreen brand hpt 2 days before my period was due and got a clear positive that showed right up and then a very very faint positive. I waited 2 days and took 4 more 2 clear blue digitals and 2 cheap rite aid ones...and they are all negative? Could i still be pregnant or could those 2 tests just be inaccurate?