no period! false negative?

hello ladies! my husband and I have been trying to conceive for 6 months now and we baby danced on my ovulation day and august 18th! my period is 11 days late and I tested Friday but it came out negative according to the app my last ovulation day was July 31st, is it possible that it was a false negative and there’s no chance i could be pregnant? has this happened to any of y’all?