Help! Amniotic fluid leak?

I need to know how I can distinguish amniotic fluid from a urine leakage. I am 35 weeks 3 days pregnant. Earlier in the day my bf & I had intercourse. Maybe an hour after I went to the restroom & noticed my underwear was wet, most of it was clear but it was tinted a bit yellow, I put a little bit of paper & waited a while to see if anything else would come out & not even 2 minutes passed & the paper was mostly wet again the same color. I don't know if it's amniotic fluid or just a urine leakage. I have been getting slight contractions but my doctor said that they weren't a pattern yet so I didn't have to worry, but just to keep track. Can anyone help me?