hyperemesis and 3rd pregnancy

this is my 3rd pregnancy my other 2 were text book everything went all to plan, now I find out im possibly pregnant (took one test and had faint line need to take another to be sure) I'm about 3 weeks 3 days if my calculations are right, there last 2 days I have been having bad nausea like I want to be sick but nothing coming up, I can't eat because I don't want to basically, but I'm drinking fine, I just spoke to my doc on the phone and she said she can't give me any medication because I am not throwing up and so to give it a couple days and wait to see if I do, has anyone had great pregnancies and all of a sudden there next pregnancy they had hyperemesis, I have a strange taste in my mouth too that feels like I've eaten biscuits (I havnt) and the after bits are still there but there isn't,