Weekly weigh-in leads to tests from the doctor

So, got weighed yesterday and we are a bit concerned because I spent almost the whole week with my Mam and so ate the same as her, but where she hasn't been to the gym but I've been doing extra dog walking (Bella seems to need to go like every 3 hours) you'd think that either I'd have lost more than her or we'd have lost the same. Or, at the very least I'd have stayed put still, right? NO! I put on 9 lbs. But, Mam lost 1 lb. OK, so we're both like "WTF???" And we asked my Dad about it and he comes straight out with "that's not right, weigh again!" Which I did, and when it came out the same he said "go see a doctor ASAP!" And then I told my Nan who's reaction was "are you pregnant???" (To which I said "no idea, would be nice though!") Anyway, called the doctor first thing this morning (since it was 11:00 pm by the time I got home last night) and he says he wents to do a few tests. It'll be hard for me to pick up the forms for it today since Kelly's out and I'd be gone too long for Kero to deal with and there's nowhere safe to put the dogs outside the doctors' office. So, Kelly's going to pick them up on his way home and then I can go see about doing them. Now, had I just put on a lb or two, fine. But it's the amount! Especially when you think last week - I think it was last week - I didn't loose anything and yet had been eating some of every kind of take-out I can get to, not to mention cakes, chocolate and cookies galore. Yet, this week I've watched what I've eaten. Plus, like I said, I'm doing more walking. I mean, Monday I was in town in the morning, walked the dogs about 3 or 4 times and then was back in town in the afternoon for a vet trip. Then Tuesday I walked the dogs, went to town, came home and walked the dogs again then walked them again before I went to bed! And that's just Monday and Tuesday. And, that's also without taking all of the constant trips outside in the yard with them into consideration. I mean, with Kero I would just let him out and watch from the doorway, but until she's had her second shot I have to watch Bella very closely so I've had to go and wander around the yard with them every time they so much as have to pee! I couldn't walk more if I tried!!! So, how the hell did I put on 9 lbs??? Even over Christmas when I was eating nothing but chocolate, pizza, mince pies (with squirty cream) and cookies it took me like a month to put on 12 lbs. So, how did I get 9 lbs in one week??? Going to get these tests done and hopefully one of the tests will hold the answer!