Did I miss my surge?

Hi ladies! I am recently trying again after a MC at 7 weeks. We were trying x 4 months but only had been using pee strips x 1 month when we got pregnant. Well I started testing the 2nd which was around cd 18. My cycles have been long- between 31-41 days. I bd on the 6, 9, 11, 13 and glow said my fertile window was 7th-13th. When I got pregnant last time I think I ovulated cd24 but I was testing twice a day and I had a much clearer surge. Do you ladies think the darkening on the 6th could have been the surge? Should I stop testing?