I have a hard-ish swollen groin lymph node. ive had it for a couple months now. its about the size of a pea. i had a urine test and ultrasound came back clear. what could be causing it? its not tender but it does cause little cramps here and there?

Inguinal (thigh fold) masses can be enlarged lymph nodes from skin infection (from entire lower half of the body) or an STD (like syphilis, chlamydia, gonorrhea, or herpes). They can also be benign masses (epidermal cysts or lipomas) or malignant tumors (lymphoma). A normal ultrasound and urine result is reassuring; STDs can be checked with blood tests. Surveillance is necessary to see resolution

You may feel the nodes every couple of weeks, if any of the lymph glands doubles in size, becomes painful, ulcerates, or other nodes become enlarged, or you develop fever, or lose weight, you should see a doctor. Wish you good health!