If you used protection, there is not too much to worry about. There are stds that can be transmitted even with condom though, like syphilis and herpes, but only if the lesions they leave on skin touch your skin. You would have seen those lesions in that lady's lips.
Sometimes irritation can be just because of the physical effect of sexual intercourses.
I want to mention that.she used lube and several time kissed and oral contact under the shaft.whie intercourse I wasn’t Fully sure about doin it.so kept some distance with her genitals.my private partsi had removed protection before finishing but to finish by my self.not touching her private.body parts.and washed my shaft with water holding the head upward .i cannot recall she had any visible sore or the lips.i a writing this after one day