Lymph Node in Groin that Comes and Goes

For the past 6 months, I've had a lymph node become enlarged in my groin (at my panty line). This occurs every month about 1-2 days before my period starts, and the node stayed enlarged until the end of my period. At the end of my period, the lymph node "goes back to normal" (i.e. is no longer enlarged). However, this process repeats itself every month right when my period is about to start again.
I have also noticed that the skin directly above the place where the enlarged lymph node occurs is also slightly darker than other areas near it. It is darker even when the lymph node is not enlarged. The node, when it is enlarged is slightly tender, but I can walk, run etc. without any problems. Just slightly tender when I touch it. It starts off as the size of a pea, and goes to about the size of a small half grape.

I'd appreciate any help I could get. Thanks! (I have made an appt to see a doctor, but was hoping to get more advice.)

[Fernando Roque, MD]

Hi.  That episodic lymph node enlargement during the time of your menstruation may be a sign of recurrent infection.  It is not uncommon for women to have urinary tract infection   around the time of their monthly period.  If the infection is mild, the symptoms may be too non-specific, so this may go unnoticed.  Maybe you can have your urine checked during the time the lymph nodes enlarge, just to check this theory.

[aquariansun]

I have the SAME PROBLEM! But I have instead of right before menstruation, it's usually around ovulation. Lasts for 3-4 days and feels better after being massaged with Arnica. I've been told many things by doctors: mittleschmerz (but it's too low to be the ovary); possible inguinal hernia (didn't get worse during pregnancy—disappeared while pregnant). I also have recent hip pain on same side & some occasional discomfort when emptying my bladder; but those are more recent complaints & i've had this swelling for many more years (>10). It's so annoying, and I just don't want it to be anything serious. I wish I could find a practitioner who could give me a definitive answer. Have you found anything else out?