Missed Period : Day 35

I was staying pretty regular. For about a year I had my period around the same time each month. Except now I’m day 35 of no period and although I try not to stress or think about it “so that it comes”, I can’t help but feel really annoyed. I took a pregnancy test yesterday and it said negative. There’s a verrrryyyy faint line that would make it positive but i think it’s just my imagination. I don’t even know what is happening! I’ve been meaning to make an app with my gyno but I’m just so busy! Also I would not mind being pregnant, I’m in a VERY stable relationship and closer to my 30s than my 20s....