Only you know if you penetrated and you think you did. Any penetration is a risk, but likely the lady is negative since she didn't want penetration to happen. I would relax and forget about this encounter for 4 weeks, then take a duo test - a duo is conclusive after 4 weeks, so a negative means you will be able to move on from hiv fears.
If your penis was in her vagina without a condom, that is a risk. Extremely low though at less than 2 percent transmission if the person has hiv and ZERO if they don't (and they probably don't). Take a duo test at 28 days if you inserted. Only you know if you did so if you think so, then yes, take a test to be sure but again, the risk is extremely low.