Hello there -
Take heart and remember that not each pregnancy is the same. I had 3 and never had any nausea with any of them. But because of that and your weight loss and your concerns that this is so much like before; I would go ahead and see your doctor - because he or she can give you the actual answer(s) you are looking for. Go ahead and do it, sooner than later and God willing, you can put your mind to rest! Let us (me) know how you are doing, if you get the chance! Take care now ...
Every pregnancy is different. Weight loss in early pregnancy can be normal, but usually because the women has appetite loss or sickness/nausea. Since you don't have this I would speak to your doctor. Might be something else going on causing this but better to be safe than sorry - especially in pregnancy and so consulting any issues like this with your doctor is the safest thing to do.