Weight at a standstill

When you drastically cut calories (below 1,500 which is what the average body needs just for basic functions every day), your body will often compensate by going into starvation mode; saving what it can. That can cause you to plateau or even gain weight. It might not hurt to increase for a couple of weeks to see what happens.

That said, activity 9ften causes a switch from body fat to muscle (which weighs more). It's not uncommon for people to briefly stop or even gain weight as done of that weight transitions.

Good luck!

No you shouldn't be eating so low.
Two weeks is far too short a timescale to judge your weight trend and you haven't mentioned what happened in the preceding four weeks.
Starting a new exercise routine frequently causes soreness/inflammation which results in a water weight gain.
It could just be a totally normal hormonal weight fluctuation.

And no you haven't added a significant amount of muscle "going on a treadmill" for a couple of weeks and while eating like a bird!

If you want more specific advice about what is a reasonable calorie level for you you need to provide context.
Only you know your age, your weight, your profile is blank and your diary is private. You really are a blank canvass!

You have undercut the minimum level for a female this site will allow and even that mimimum might be unsuitable for you.