I have had one swollen lymph node on lower left side of neck. it is not very large - the size of a small pea. noticed it after having covid in december (its april). it has decreased in size since first noticing. not painful. should i be concerned?

Lymph nodes are located throughout the body & generally noticeable in exposed areas like the neck. They are usually PEA sized at rest and enlarged when stimulated by bug bites, dermatitis, drainage or infection. They rarely can become damaged by infection & grow to golf ball size & need drainage or removal. The node as described is normal.