Welcome back to the forum.
Presumably "penis inside me" refers to your rectum, not mouth. On the one hand, receiving anal sex is the highest risk of all sexual practices. OTOH, you give strong evidence your partner doesn't have HIV; most people don't lie about HIV status when asked directly, and most really don't want to infect their partners. There's always a small chance he has HIV and doesn't know it, either because he wasn't tested recently or has acquired HIV since his last test and could be in the window period before a positive test result. However, the statistical odds are low for both these possibilities.
If your blood test at 11 days was a duo or combo ("4th generation") test, it's probably around 60-70% reliable; or if testing included HIV DNA/RNA testing, it's 90% or higher. Either way, I would suggest you wait another 2 ½ weeks, and have a combo at 4 weeks after the last exposure, which would be conclusive. Alternatively, the quickest way to definite reassurance would be for your partner to be retested at this time. If negative, you could be certain he wasn't infected at the time of your last exposure.
Whichever path you choose, stay relaxed in the meantime. The chance you were exposed or infected is very low.
I hope this has been helpful. Best wishes and happy holidays-- HHH, MD