Age 26 – Pre & Post Coitus
This heterosexual couple is not trying to conceive, which is why they chose this infertile day of her cycle to have unprotected sex.
Both photos are taken on the day before she began bleeding – you can see some fresh blood at the os. The first is pre-arousal. The second is taken about an hour later, after both male and female orgasm. You can see a pool of seminal fluid on the bottom. The cervix was much farther back in the vagina during the second photo shoot due to the ballooning of the vagina during arousal.
The “up-suck” theory describes the cervical contractions and dipping in and out of the vagina as an evolutionary advantage of female orgasm. This theory posits that the rippling muscle contractions of the uterus and vagina during female orgasm shift the pressure in the uterus also causing the cervix to gape and suck (imagine a turkey baster if you rhythmically squeeze it). The dipping, gaping, and sucking movements of the cervix will help draw in the semen that is present in the vagina into the os and uterus (particularly if there is fertile cervical fluid present). Some say this theory is a myth. If the speculum weren’t opening the vagina, the os would be resting in a pool of semen.