When I had mastitis, I used a vinegar and water combo that was like one part of vinegar to four parts of water. It felt refreshing, rather than sting as one might imagine it might.
I'd suggest a vinegar/water sitz bath to anyone with anything irregular happening in the tender lower region, not just a yeast infection. It's not harmful, is the first point. Vinegar has been tested and found to be antiviral, is another good reason. And besides, it's kind of refreshing. (I assume from your response that you know I don't mean a douche, but it's worth saying that I don't, since cider vinegar is a classic ingredient in some home douche recipes.) I was talking about sitting with your behind in one of those Rubbermaid bins they make to do dishes in the kitchen sink, but a bath in the tub would work too if you felt like expending the vinegar. (The nice thing about the bin plan is that you can do them several times a day if you want without much fuss or going through your gallon of white vinegar all that fast. Just prep it, put the bin in the tub, and sit in it.) Possibly someone else who uses a white vinegar and water solution will write that a one part to four parts concentration is too strong, but when I used it on my poor, cracked breast when nursing, it was fine.
I just started my antibiotics today, and it's a ZPack, so hopefully it's just the tears and friction blisters (I hope!) with maybe a uti thrown in for good measure, since the pain is on the inside AND the outside. I had planned to let the antibiotics run their course and see how I felt when they were done, but I figured posting here in the meantime could give me some other opinions.
Annie - would you suggest the vinegar sitz bath even if it's not a yeast infection? Will the vinegar bother the tears? Would a regular soaking bath be ok? What's the ratio of vinegar to water? (that's a lot of questions)
sorry, "what is happening," not "what it happening."
If you're on antibiotics now, it isn't going to hurt anything to wait and see if what it happening came just from the friction. It's not like any STD out there is going to knock you out for the count in the next two weeks.
That said, if it is an STD, it's possible that the antibiotics won't touch it (depending on the antibiotic and the STD). If it's the wrong antibiotic or some kind of STD for which antibiotics are not an effective treatment, you're going to need to get tested pretty soon anyway.
In your shoes, I'd take the present run of antibiotics and see what the deal is in that time with your ladytown. If it begins to hurt more, I'd suspect either that there was a tear that needs attention, or that the antibiotics are giving you a yeast infection on top of everything else. I'm also a natural-cures girl myself (without being idiotic about it) and I do always recommend a white-vinegar-and-water sitzbath to anyone with difficulties in their lower area. White winegar is both a antibacterial and an anti-viral substance.