Should I be concerned about a reoccurring rash that looks like a petechial rash?

[Babygirlblue]

Any thoughts as to what can cause this type of rash to be reoccurrent on the lower extremities i.e., hips and buttocks?? They look like swiggles - closest looking picture is one of a petechial rash though these marks are not a circle.
Rash appears on one hip then disappears only to reappear on the other hip or sometimes the buttocks.
The rash does not hurt or itch and feels smooth to the touch as if it is an injury under the skin.

Accompanied with
Unexplained weight loss (around 100lbs)
Chronic fatigue
Excessive night sweats
Excessive dizziness/fainting
Over all joint and bone discomfort though especially localized to left arm
Easy bleeding and with unusual heavy and frequent periods ( twice to three times a month)
Frequent infections - Especially of the upper chest.

20 year old female experiences symptoms.
With no regular medications besides an implanted birth control for two years.
Rash and symptoms onset began around 5 months ago.

Any information or foresight would be highly appreciated Thank you.

[Emily_MHManager]

I agree with CurfewX.

Losing 100 lb with no explanation in 5 months is really very concerning.

[CurfewX]

You have a lot of concerning symptoms, particularly the unexplained weight loss of 100 lbs.  The rash is likely the least of your concerns.  You need to see a doctor for blood work and diagnosis.