21 days post ovulation and 3 days late

I'm so, so confused. We've been TTC for 7 months. This past month I switched from the $store OPKS to the clear blue digital with the 🙂. It said I was at peak on day 9, different from the $ store ones that for months were consistently around day 15!  So, now I am at day 31, 21 days post-ovulation, and 2-3 days late past my normal 28-29 day period. I took a test this afternoon and it was negative. What could be going on? If I am preg, would the afternoon urine affect the test? It shouldn't since I'm 21 days post ovulation, right? I have only had one 31-day period and that was the first one after I got off the pill, 7mos ago Help! I'm going nuts.