You need to let your body process the pregnancy in the way that it needs. If you are exercising (and feel good about it), and eating a nutritious, balanced diet, then that’s really all you should do. Pregnancy really is a time to sleep when you’re tired and eat when you’re hungry. You also don’t know how your body will prepare for pregnancy–so yes, most women gain a modest amount in the first trimester, but some women lose weight because of morning sickness, and some women gain a little more because their body determines that’s what it needs. I threw up for a week straight and ate practically nothing and STILL gained weight in that same week with my first.
And I have some perhaps unsettling news for you–unless you are one of the few women who don’t experience morning sickness, I think that most women find the first trimester very difficult on their bodies. For me, it became impossible to exercise and also impossible to eat healthy–I pretty much ate licorice, crackers and skittles for several weeks because that was all that I felt like eating. Now, I could either get really stressed out over this or I could be kind to myself and just get through it. And my OB was one to tell me that the first trimester is really about survival–just get through it in whatever way you can (okay, don’t smoke crack, but you kwim). I’m just saying this because you’re only 6 weeks now and most women won’t start to feel it around 8 weeks, give or take, and I think it’s helpful to be reminded that your body may force you to let go for a while.
The other thing to remember is that chances are, if your weight gain is within a recommended range, you NEED every single one of them. I heard an analogy that’s true: building a baby is a bit like building a car. You not only need the raw materials and the tools, but you also need a stocked garage to support the building of the car. Your body is the same way–it’s not just the baby and the placenta, it’s also the additional resources (your blood volume, fluids, and yes, stored fat) that the body relies on to nurture and grow that baby.
If it’s any consolation, I was overweight when I got pregnant and ended up gaining 12 pounds, all told. I ate a reasonably healthy diet but I did go from vegan to omni while pregnant and definitely ate my fair share of cheeseburgers and ice-cream, and I also stopped running and doing yoga in favor of walking–I didn’t have to “work” to keep my weight gain within an acceptable range for my starting weight; my body just did it on its own. I think that many women are similar, tbh.
And finally, this is your moment to start understanding health more holistically, such that you really should be focused on how you FEEL, rather than how you look or the numbers on the scale. Worry about the quality of your diet, not the quantity of food (or calorie intake); exercise because it makes you feel good and brings you energy, not because the scale is telling you xyz. And go beyond that, too–take care of your teeth, manage your stress, get good sleep.