‼️ (HELP!) Rapid Weight Gain, Should I Be Worried?

So a few weeks ago I moved out of my parents’ home, and due to the bad circumstances there and lack of actual caring from my parents I wasn’t eating as much as I should’ve been, which is what I blame for not gaining as much weight as I should’ve been (according to my doctor). But a couple weeks ago I moved in with my wife’s parents, who are much more compassionate and I am now able to eat as much as I should, and am now catching up with weight gain. I gained about 5 pounds in the 3 weeks between doctor appointments, which I thought was great. I’m now 29 Weeks. At my appointment last Friday I was 106 (yes, I’m quite small and was underweight before pregnancy). Yesterday (Tuesday), I weighed myself on my sister in law’s scale, and it said 112, and I thought, that’s crazy, no way can that happen in 4 days. I stepped on it again and it said 113. I figured the scale was a bit off, but when we got back home, I used the scale we have here, and it said the same. I know that rapid weight gain can be a sign of preeclampsia, but my blood pressure is consistently on the very low side of normal at every appointment, including last Friday. On Saturday night we went out and had a HUGE dinner (more than I’ve ever eaten in one sitting 😬😬😬), so I thought that could be the cause? I have been eating a lot in the past few days because of the holidays, but 6-7 pounds in 4 days freaks me out. Should I be worried??