First off: There's enough bullshit in this world without potentially missing a life-saving pap smear because you had a bloody vagina. If it's a choice between going to the gynecologist when you're on your period, or not going at all—go. Moderate social embarrassment is not worth dying for. There are paper sheets on the examining bed for a reason.
But is it okay to go for a routine check up when you're on your period? Like Khloe Kardashian's paternity, this is one question the Internet doesn't have a conclusive answer on. The consensus generally seems to be that—like Lady Gaga's post-2009 career—it's probably best avoided, but it's not a disaster if you must. Besides, scheduling an OB-GYN appointment when you're not on your period is difficult, because most women don't know when their period is due. (I hear they have apps for this, but who has memory on their phone?)
"The short answer is yes—if it is urgent—but it's best to leave it until after your period if possible. It really depends on what you are seeing your gynecologist for," explains Dr. Narendra Pisal of the London Gynaecology clinic.
If you're due for your pap screen (also known as a smear test), Dr. Pisal advises rescheduling if possible. "However if you need a consultation for acute symptoms such as pain or infection," he warns, "a bit of bleeding will not get in the way of making a diagnosis." Basically, if you're in pain or scared there's something urgently wrong—don't put it off.
If you've already had a smear and it came back abnormally, (and you're due for what's known as a colposcopy examination), it's okay to go to the OBY-GYN when you're ragging. "This is safe and possible to do during a period," Dr. Pisal advises. "Many women would much rather get reassurance urgently when faced with an abnormal smear and there is often no need to wait."
Finally, if you're thinking about getting an IUD fitted (do it, they're great!), it's actually beneficial to do so when you're on your period. "It's an ideal time to do fertility blood tests to assess your ovarian function," Dr. Pisal explains.