Lactating, headaches, acne, chin hair, weight gain, Pregnant

I am lactating, having migraines a few days a week, I have grown chin hairs (doesn't normally happen!), gained weight (especially in stomach),feel very sick to my stomach in the mornings, and I have gotten pimples on my face, chest, and back (doesn't normally happen). I thought I was pregnant when I realized I was lactating out of both nipples and ignored the other symptoms and took 2 pregnancy tests which were both negative. I hadn't had a period in 3 months (just gotten off of seasonale birth control) and then had one last week which was very light bleeding and only 3 days. Could I be pregnant or do you think these are all symptoms of something more serious. I read that these symptoms could be signs of a Pituitary tumor. Just want some advice.

go get a blood test to see if you are preg. most likely your body is just reaclimating the creating its own estrogen and other hormone levels. you will probably be out of wack for a while seeing a seasonal hindered your periods in such an extreme manner
i know that when i go off birth control i get bad acne and my boobs hurt at first but those are things that would happen is i wasnt on it in the first place, it usually calms down, so maybe give it a while

I would urge you to get your doctor to do some hormone tests such as 24 hour urine collection for cortisol levels. Many of your symptons are ones that could be related to a pituitary disorder such as Cushings Disease. These are realtively rare but only because they are often undiagnosed for so long and are put down to other causes. Often the weight gain is just around the middle, face (moon face) and upper back (moon face). I myself was misdiagnosed for over a year with problems such as PCOS, acne, strained back muscle, reaction to pill, stress and depression. All these where however finally recognised to be related.
There are also a number of endocrine disorders but i advise you to look into this area!!