How do I add up my paid time off/regular hours/overtime for my paycheck?

This may be kind of long and convoluted, but please help me out!

At my job we don't get sick time or vacation time, instead we get paid time off (PTO).

Our company policy is that PTO hrs count as hrs worked!

So this week on Monday I scheduled 3.25 HRS of PTO from 2:45 to 6:00 p.m. for an appointment, but I was actually able to start work at 5:00 p.m. and ended up working a full 8 hr shift.

Then Tuesday I worked 8.5 hrs

So far today looks like it will be a 10.25 hr shift.

And let's assume Thursday and Friday will both be 8 hr days.

Now at my job you don't actually get paid overtime until after you've worked 40 hrs during the week.

So basically my question is even though I started my Monday shift late because I scheduled time off, since I still worked 8 hrs I'm not sure if my employer will subtract the 3.25 hrs of PTO from my total available time, and will those hrs end up counting toward my total hrs worked for overtime?

Basically will Monday be considered an 8 hr day with no PTO used, or will it be an 11.25 hr day and lose the 3.25 hrs from my total available time?