Epileptic missed period false negative????

Okay so I’m epileptic and quit my birth control about 10-12 weeks ago my boyfriend and I had sex a week or so after i quit taking it. and we’ve had sex a few times recently and a few times were on my fertile days according to my period app. After I quit the birth control we used protection we always have regardless. My period ended up being a week late and I had spotting very very lightly for about 4-5 days and I haven’t had a period at all since. my periods were very irregular on any birth control I was on though. I’m almost 7 weeks late and I’ve taken three pregnancy tests and they’ve all came out negative but I feel pregnant I’ve got the missed period the nausea tender breasts headache fatigue all of it except for the puking. Certain smells are messing with me And I’ve gained almost ten pounds within two weeks. Twins run in my fathers side of the family. Is there anyway that I could be pregnant and the tests are false negative?????????