What is the ruling on my prayer when I think about sex and I don't know if anything came out of me, and sometimes I repeat ablution, and when my husband passes by I feel as if my ablution has been invalidated? Is this doubt?

These thoughts do not invalidate the prayer, nor is the prayer invalidated by doubting the emission of something from the person performing ablution. Rather, there must be absolute certainty of the invalidation of ritual purity. So, as long as this certainty is not achieved, the prayer is valid, based on the Prophet's (peace be upon him) saying: "He should not leave until he hears a sound or perceives a smell." It is advised to strive in guarding one's thoughts during prayer and to ponder upon the verses recited and the remembrances made.