There is no way of determining risk, someone either has herpes or they don't.
You have had no genital cold sores by the sound of it, hence this represents a very low chance of genital herpes.
So my encounters sound low-risk? I'm sorry to bother you and i plan on seeing a nurse tomorrow but peace of mind would be amazing right now.
You are not describing any symptoms of herpes, it is most unlikely you have genital herpes. Hence I see no real reason to test, unless you wish to do so mutually with a prospective partner.
If you can't accept this as the likely case for you, then obtain a blood test, the choice is up to you in the end.