Hey! Firstly, congrats on losing the weight and your determination to lead a healthier lifestyle! 
I’d like to echo what the other guys said: weight definitely fluctuates a lot – I weigh daily and sometimes it goes up, sometimes it goes down…and this is what I tell myself to account for the variation (especially if I know I’m doing everything correctly):
- Water retention
- Food weight (you could have eaten a bit later the day before)
- Waste weight (had a satisfying No.2 yet?
) - Muscle gain
- Shifting your weight on the scale (depending on your scale, standing differently can have up to a 1kg difference!)
- If you’re a female: It could be the TOM
- The ‘Whoosh Effect’: Sometimes, your fat cells are still holding onto water, which could cause you to maintain your weight for ages or even increase. I often find that when keeping my habits consistent, the scale increases slightly just before a loss, then dips down below what it was maintaining at the next day.
If, after a couple of weeks (say 2-3 more), it still doesn’t go down, perhaps your calories are too low? Especially if you’re exercising so much. If there’s anything I’ve learnt from my days of extreme restriction, it’s not the lower the better; if not, we’d all be sticking to a 500kcal diet to lose the most weight fastest.
Tl;dr, don’t be disheartened, you got this! 
Update us as to how it goes