Yes and no, in Exodus (21:10) it is quite clear (not from the English but from the Hebrew) that when a man takes a wife hi must grant here conjugational rights. The Talmud even went further asking how much is enough, and had a simple answer: If the man is unemployed, once a day, since he has nothing better to do. If the man is a day laborer, the lord gave him the Shabbath to rest, and thus once a week is required. if the man is a donkey driver, he should come home and "deliver" at least twice a month. As for a camel driver who is expected to stay on the road longer, once a month is the required quota, and a sea farer should return and discharge his responsibilities at least twice a year. The wise talmudic rabbi, trying to classify their own duties in the matter, finally decoded that "Talmid Khacham" (wise man or student) have that obligation at least once a month, so as to not distract them from the study of the Torah, but they added, (for all cases)" vekhol a marbeh, harei ze meshubach", meaning, the more, the better....
Sure, you are not allowed to spill your seed in vain (thus masturbation is forbidden) , but there would have been prohibition of conjugation during pregnancy, and there is none, so the rule is the sexual needs of the woman count and should be given (et onata titen la).
Zeev
