I'll give you my best guess. I would suspect that fear of pregnancy ranks fairly high for most heterosexual women, because the burden of an unwanted pregnancy, whether it ends in adoption, abortion, miscarriage, or keeping the child, is almost entirely on the woman. Pregnancy is hard on the body and involves some degree of risk even for healthy women, and an unplanned pregnancy can cause a woman problems socially, educationally, financially, spiritually, etc. Lesbian women obviously don't have to worry about pregnancy, but I would guess that a common worry for lesbians might be who does what to whom . The only images of sexual lesbians available in the general culture are the sterotyped, fake lesbians seen in porn films which are generally made for a male audience.
Many lesbians also report being worried about their body image , especially as they get older.
Men are supposed to initiate sex and take the lead in a sexual encounter, and they are supposed to be able to get hard and stay hard whenever they want. And while a woman can have sex even if she isn't very aroused, a man's erect penis is more or less required for intercourse. Although there are many pleasurable sexual activities which can be shared if a man can't get or sustain an erection, most men find even an occasional erection problem to be so embarassing and shameful that it precludes any other kind of pleasure for them. I imagine gay men share the concern about who does what to whom with lesbians, for many of the same reasons. Many gay men also worry about HIV and other STDs.