How soon will I start feeling morning sickness if I'm pregnant with twins? Will the morning sickness be worse than if I'm only carrying one baby?
Twins are exciting, but it can be a little scary to anticipate the pregnancy experience. So, first off, remember that not everyone feels awful in early pregnancy—even moms carrying twins can occasionally sail smoothly through those first few months. That said, you are right that on average, pregnancy symptoms like nausea and fatigue may be experienced more strongly by moms carrying multiples. Pregnancy hormones, which cause these early symptoms, are higher in twin pregnancies.
In general, morning sickness, sometimes called NVP for nausea and vomiting of pregnancy, can start as early as week 6 from the last period (the fourth week after conception). I have not heard that twin symptoms start earlier, but they can be more severe. When a mom who has not yet had an ultrasound presents to the hospital with hyperemesis gravidarum (vomiting that has led to dehydration or metabolic disturbance), the medical team always checks for twins as part of the workup.
It sounds like you are someone who likes to be prepared for the worst. See if you can get in to the mindset of taking this one day at a time instead of trying to predict all the bad things that might happen. You will have good days and bad days in pregnancy. You may feel awful for a while, and you may feel ecstatic at different times as the babies become more real to you. If you have severe nausea and vomiting, talk to your doctor or midwife about what you can do to manage symptoms and so that you can stay hydrated and get in some nutrition. And remember—pregnancy always ends, and you will have two new members of your family to love forever.