Pregnant or nah?

So my period is ALWAYS either on time or maybe 1-3 days EARLY. Well as of today , August 7, 2017, I am 17 days LATE. I took a pregnancy test at day 2 of missed period and day 4, but now I'm on 17. I don't know what's going on. Both test said negative. I am not having any symptoms either way. June, I could have sworn I was pregnant but had a period . July - no symptoms, I feel fine, no cramps , nothing. I had cramps the first day but after that I feel fine?? Could anyone give me advice on what might be going on or what I should do? I've never been even one day late(except my 1st pregnancy, which I had all symptoms of) so can anyone help me ? Thanks !