Weight loss in pregnancy

So I'm pretty sure I'm ok being tht I'm over weight already but I'm starting to get worried. I am 11 weeks and I keep losing weight. Now I'm at my smallest. Baby is still growing fine first appt I measured exactly what  I was supposed to me 8.4. I had another appt at 10.5 where baby measured 2 days early at 10.3. I was only nauseated, never threw up at all. But I just want to make sure I'm eating enough