Weight?

Ok ladies, splain this to me. I've been trying to loose weight for a few weeks now. I don't have a bathroom scale, so I can't check at home to see what I weigh regularly, but I'm 99% sure what my starting weight was. About 3 week's into smaller portions and YouTube exercise videos for beginners (cough cough* lie*, so not for beginners!) I went down a pantsize and my bra was too big. Fastforward to a trip to the er for an unrelated issue. The nurse asked me how much I weighed. I explained the loose clothes an that I honestly had no idea. She lets me step on the scale right? IVE GAINED 5 LBS. How in the hell did that happen?! Been so upset I haven't done a single crunch or squat for a week now. :(