Miss Lutzke's Journal, 19 May 2016

I think you were in a true plateau and now things are moving again. Most people believe a plateau is a week of not losing, but it is generally months. And you lost a large amount of weight (congratulations - very impressive!) so your body probably is adjusting to the new you. Your metabolism might have picked up a bit. If in addition you are not feeling well though, you might consider a physical. 

It could also be because people usually gain muscle mass when they start to work out heavily; since muscle mass is denser than fat, you actually end up putting on weight for a brief period after starting to work out (say for the first 2-4 weeks?), but you SHOULD eventually see overall weight-loss over time with a good diet and exercise. I'm not an expert but I think that's basically how it works. I'm in the same boat, so I'm actually going to try to cut my daily calorie intake a little more than FatSecret suggests as my daily recommended caloric intake to avoid this. 

sorry..realized I didn't really answer your question clearly...basically, you maybe laid off gaining muscle mass by not exercising as hard, so who knows, maybe you hit on the perfect balance of exercise intensity, exercise frequency and diet!  

I don't think it's a red flag at all. You didn't work out as hard so your muscles aren't retaining as much water. You might have ate more calories which kick started your metabolism. Weight loss is a strange thing. You can stay the same for 3 weeks and then have a nice drop. Take the loss and keep going. Sounds like you are doing fine.