I've had morning sickness since 6 weeks. However mine is triggered by smells and unfortunately also by constant gagging (automatic reflux). For me it comes in waves some days ill be great and then all of a sudden ill be sick. I also get nausea throughout the day. My midwife couldn't give a monkeys, even though I weigh 8 stone and I'm 4"11, loosing weight is very dodgy for me. I'm now 17 weeks and I'm still suffering and still loosing weight. The only things I've found that help is eating tiny portions of anything you fancy. I always take a bottle of water with me where ever I go and sometimes fresh lemon slices in the water help.
This is my first pregnancy and sorry to sound negative but I'm not enjoying it one bit. I've also got the lovely piles, so when I do get a chance to eat something, I then get that issue to contend with.
I hope that your morning sickness eases up and that you get to enjoy your pregnancy. Xx