All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
We advise you to ignore Waswaas (obsessive whispers) completely. Do not consider that you discharged urine until you know this with certainty to the extent that you can swear to it. As long as you do not know that with certainty, do not clean yourself or your clothes.
If you doubt whether what is coming out is urine or natural moisture, you should choose one of them and act upon the relevant ruling, according to the view adopted at Islamweb. In this case, there is no harm in considering it vaginal discharge and, accordingly, you do not have to wash it. You only need to perform ablution.
Allah knows best.