Am I at resk of hiv if the tip of a penis enter my anus no ejaculation?

Low risk, not zero. The chance of getting HIV from such an exposure probably is very low, but it's not possible to say there is no risk at all. The risk of other STDs is higher. You should not allow any such contact without a condom, unless you know for sure your partner does not have HIV or STDs. All men having sex with men should have HIV/STD testing from time to time. Maybe now is a good time, when on your mind.