Large lump near perineum

Hi, About 2 weeks ago I noticed a large tender lump to the right of my perineum (between vagina and anus) its about the size of a grape. Its to one side and in between so I can't really tell if it's connected gynaelogically or anally- or even if it is either! its feels quite hard- its not overly painful and i can only feel feel it if I strecth or am in a certain position. Anyway I was worried as I have Crohns disease it may be an anal abcess (abscess) (or worse). I went to the doctors this morning and I'm no further on as the doctor didn't know either. I've been put on fluoaxcillin antibiotics and have to go back tomorrow for a blood test. But I've been referred to the hospital for an Ultrasound test.

Just wondered what your opinions of this are and if anyone has gone through or had similar symptoms/experiences to myself. I'm particularly worried as I'm getting married and going on a very active honeymoon in 2 months and everything points to having a relatively long stint of aftercare.

thanks and sorry for the long post x