What if i forgot to write down a medicine i take for a urine test that had to be sent out?

Sent out for what?: Most urine tests are to used to look for pregnancy infection & evidence of kidney damage. As such, we don't need to know what medications you're taking to interpret the findings. However, if your urine test is looking for specific drugs/substances, your ordering doc should know everything you take and be able to account for that. If s/he doesn't know, you better tell him/her & lab ASAP.