Hi. I hear a lot of times that BP is diagnosed after Depression is, and the antidepressants don't help, or the person tells their doctor about the feeling way too good, as well.
Generally, people with bipolar, rather than unipolar depression sleep too much, and people with depression can't sleep.
as well as that People with depression don't eat, and people with bipolar eat too much.
(again, this is just what is true for a lot of people, and doesn't necessarily have to be true to you)

There are two sides to being bipolar (obviously) depression, which you have, and mania (or hypomania if you're bipolar II) Describe your happy moods to your doctor, and they will decide if they meet the criteria for mania or hypomania. If they do, then you will be diagnosed with BP because the depression part of it has already been established.

good luck!