Can I Be Pregnant?

I know I've updated too much about this topic, but I'm still confused:
I've taken two pregnancy tests, both different brands (First Response: Early Pregnancy Test and E.P.T: Early Pregnancy Test), and they were both negative. I haven't had my period for 16 days and today is my last day of ovulation, I last had sex on a week ago maybe? I'm not completely sure about that, but it was the day before I started ovulating. (I'm accurate because I have an app on my phone that I can record the days I have my period and such.) I'm not sure about all of this, but some websites are saying that I should wait til after I stop ovulating, or wait til next month to see if I get my period between then or then, to take another test. I've only got some suspected pregnancy symptoms: tender breasts, no period (obviously), extra discharge, rapid headaches, cramps in my lower back and abdomen, and I've been craving things like green olives, salt, tuna (I'm a vegetarian and have been for about 6 months so this is unusal), and a lot of bloating. Half of me is thinking it's my period withou the blood, but that doesn't make much sense because the blood is the main part of having a period since the unfertilized egg had a soft wall lining and it hasn't shed from me yet? Haha xD.
Please, some advice would be very much appreciated. Thank you. :3