He didn't say that. There's no way anyone could tell you with certainty that you'll be fine. Even though it was brief, unprotected anal sex is a high risk activity.
You need to be tested as Teak already advised. You MUST insist on condoms for every epsiode of anal sex.
But you still feel that in this scenario I will be fine? He didn't ejaculate inside me it was only seconds he entered my anus
Yes, the unprotected anal sex, plus on top of that you might have damaged your anus by douching hence the blood.
So do you think this was high risk? The penetration was literally seconds and didn't fully ejaculate
You can obtain your conclusive negative test result 3 months post exposure.
I must add this is my first receptive encounter with a man in my whole life ( 23)