unsure of dpo any one ?? opinons please

so unsure of dpo as

femometer had ovilation confirmed by bbt on the 9th july

glow has the 18th

prenom has the 15th

so was doing my mid morning lh strip and thought ive got enough pt strips ill chance it

so this is fifth wee in time frame and i can see it straight away

so can hubby and a good friend what do all think

all tests have been straight negative prior to this on monday was nothing at all