6 days late period and slight brown discharge. Trying for 3 years could I be pregnant also I have good estrogen levels and slightly low progesterone what can I do to bring that up?

When in doubt. just check pregnancy test. And if you are still not bleeding normally and first pregnancy test was negative, check it again in 1 week. If both negative and your symptoms persist, get to a GYN so they can help you determine what the next step is to regulate your periods. I am not sure if you have been to a fertility physician but would encourage you to do so if you have been trying for 3 years.