A pill that is imprint M 037?

There isn't a pill listed in any of the databases with an imprint code of M 037.

There is however a pill which looks almost the same as your pill with an imprint code of M on one side and C37 on the other side. It would be easy to mistake the C for an O.

Pill imprint M C37 has been identified as Cetirizine hydrochloride 10 mg, which is a generic version of Zyrtec, an antihistamine used for the treatment of allergies.
There is a picture here https://www.drugs.com/imprints/m-c37-11718.html if you want to take a look and see if it matches up.