Pregnancy dreams - men other than my husband?!

I usually have really vivid dreams but this pregnancy is making them even crazier. I love my husband so much and have fallen even more in love with him since getting pregnant. We are very happy. So why, when I go to sleep, do I keep dreaming about other men? Sometimes they're people I know, other times it's some random made up guy. Sometimes I'm single and other times I'm cheating and I know it! Sometimes they're romantic and sometimes they're steamy. But they're never (or at least, very rarely) about my husband who I love. I know they're just dreams but I'm feeling so guilty!