If you’ve ever shed a tear or two after an otherwise enjoyable roll in the sack, you’re not alone. An online survey of 230 female college students revealed that almost half of them — 46 percent — have experienced postcoital dysphoria, or post-sex blues, at last once in their lives. About five percent report having PCD a few times within the past four weeks. The small study was published in the open access journal Sexual Medicine, with the caveat that a lot more work needs to be done to understand this little-researched phenomenon.