I don't believe there even is amniotic fluid at 5 weeks. As GA said, an increase in discharge is very common throughout pregnancy.
I seriously doubt it is amniotic fluid. Increased cervical mucus during pregnancy is very common. It can range from clear to white and creamy. It doesn't have a bad odor, or may have no odor at all. Amniotic fluid will be a liquid, just like urine, only it will have more of a sweet smell or no smell at all. At 5 weeks pregnant you are technically only about 3 weeks post-conception. It's highly unlikely that this is amniotic fluid, especially if it is the way you described.
I hope at this point that it is too early to be amniotic fluid!!! :-( So since we dont know what it is and this is your 1st pregnancy I would call my ob/gyn just to make them aware of what is going on and maybe is they feel they can have you come in early. I would certainly call my dr and ask. It could be all a mind thing but i dont think i would chance it especially with this being your 1st pregnancy and you dont know what to expect. Better safe than sorry. As far as the smell dont know if this is common or not. Hope this helps and best of wishes to you.