Okay, It is really doubtful that you have an STD.
The female reproductive system releases discharge as a cleansing process and it is completely normal to have thin white discharge and it can be kind of slimy too, also can have a more off white color too.
Yeast infections tend to be somewhat clumpy and do sometimes have a yellowish tint and it is obvious when you have when as the itch can be very bothersome.
I have had yeast infections and have had white thin discharge now and again and I see a gynocologist every year and I'm perfectly fine.
If it is odorless and you don't think it is necessary to see a doctor then that is your call. You may want to see one just for piece of mind.
It is very normal to have discharge, it is part of being a woman. Chances are you are fine but if you are having sex you should be having annual check-ups.
27 years old
1993: T1 to L1 fusion due to scoliosis at age 17
2000: Tore and ruptured L4 L5 & L5 S1-it finally got better after about a year. Did really well for about a year.
June 2002: Had a relapse and tore/ruptured disc again.
Now I'm 14 months into it and the pain is still there.
Can't deal with it anymore so I'm having a discectomy in Sept. Hoping and praying that it takes care of my problems!!