Being late. Or preg

I've gone from 28 days to 32 days in my months and it varies like I'll do 28 for 3 months then 30 or 32 for 2 months then back to 28 but I miss all of Sept and was 45 days late took test was not prego then the next month I was back to 30 days so the online things like this day I arv. 35 days just because that one mess up month but if I stick with the 28 to 32 days in at day 36 today do I test and get my hopes up or wait to I hit lol day 45 again. What do u guys think. Thanks any help would make me feel better