Hummmmm 🤔🤔

So, I follow this app for pregnancy, obviously, and another app called "What To Expect". Both apps are awesome and help me to keep in track of what to expect from baby each week. However, I do get confused when I look to see how heavy and how big in length baby is on each app because they both say different things. From my apts, baby is measuring a day off, not a big deal. But one app is saying the baby is about the size of a sweet potato and the other is the size of a green pepper.. Both apps are differing in weight too. I'm not very intelligent, lol, but I think those two foods differ in size a hair. So should I take the two apps and just say the baby should be within this hight and weight range for each week??? Hopefully not to stupid of a question but was just curious. Thanks! 😊