Weight gain

So before I got pregnant (I'm 5w5d) I was on weight watchers I lost 20lbs. I am now right at the top of my healthy weight my goal weight wss another 14lbs. I am still tracking what I eat just so I don't go overboard but not intending to lose any weight just yo maintain. This week I was out for tea twice and ended up putting on 1/2 a lbs I know it's not much but it annoyed me. I think I am going to struggle with gaining weight as I worked so hard to lose it before.