If you ovulated 7/26, you would be about.... 24DPO right now. I'm 23DPO myself actually. It's not common, but possible that your hormones are kinda out of wack and you COULD be pg just not have enough hcg in your urine to show.

If you are only 10DPO though, you want to wait another 5 days likely and test again. You'll have a much better chance at a BFP then if you are in deed UTD. Good luck with everything either way!