It isn't possible to calculate odds - there are too many variables. Knowing the odds wouldn't help you determine whether you have HIV or not anyway. Just get tested to know for sure. If your last unprotected intercourse was in October 2021, ANY test you take, including those you can buy over-the-counter, will give you a conclusive result.
There's just no way to calculate the odds of you having been exposed to the virus. I just think that the best course of action at this point in time would be for you to just "bite the bullet" and get tested