I felt just like you about when I was as pregnant as you!
Obviously, weight gain is an important thing in pregnancy...but most weight is gained in the 2nd and 3rd tris.
I would wager the best thing you could do now is make sure that your lack of appitite is GENUINE, and not related to other dietary influences. I would guess that your lack is probably genuine, like mine was--and I was very happy at around 15 weeks, the appitite started to kick in.
(I had been worried, because all I could remember about my 1st pregnancy was eating entire 18-inch cheese pizzas solo....fogetting that I wasn't doing that at 14 weeks, but at 36 weeks!!!)
One thing that can dampen the appitite is not eating breakfast. "eat breakfast, eat breakfast......." that's all ANYONE ever shouts, for anyone--those trying to loose weight OR gain weight!
I know that when I do eat some breakfast, I have more appitite throughout the day. So maybe something else with your morning toast would be helpful...a glass of juice, some peanut butter on the toast?
Your bean burrito is a protien-packed food, so that will stay in your system and keep you sated for a while.
Candy and sugary stuff can trick you into feeling sated and not hungry, so be aware about that & make sure that's not what's causing your lack of appitite.
I would think you'll be fine, and I'd give your body a couple of weeks to get ready, and then you'll be ready to pack in the chow.