I had the same thing when i was pregnant with my daughter and have had it again with my second pregnancy but it's not as thick...it gets so bad in the morning when i wake up that i keep paper towels by my bed to wipe my teeth and tongue off. it's horrible and thick and makes me gag. i'm mentioning it to my dr when i go back and am hoping she can tell me what to make it better. but it is very common in pregnancy unfort. and a lot of people seem to have the same problem. with my daughter like 2 days after giving birth the thick spit was gone and i was back to normal. it was weird but i was glad to see it go. it may just be something that can't be cured during pregnancy but i'm hopefull for some answers too! GOOD LUCK!