Hypoechoic Lesion

Im a 39 yr old with 2 children. Ive had my first noticeable irregular period that started on April 3rd.  It continued for 5 weeks.  Upon going to the Dr. she put me on a high dose of birth control pill which immediately stopped the period.  They did a pelvic ultrasound on May 3rd(during this cycle).  This is what they found:
A retroverted uterus measuring 8.4 x 5.1 x 6.0cm. The echotexture is slightly inhomogeneous. The endometrial stripe is thickened at 15mm.  There is no focal uterine mass.
The right ovary has a 5.0 x 3.9 x 2.5cm hypoechoic lesion within the right ovary with the suggestion of layering low-level echose.  This is suggestive of a complex cyst.  The left ovary is not visualized.  There is a small amount of pelvic free fluid.
Impression:
Thickened endometrial stripe at 15mm.  Defferential considerations include endometrial hyperplasia, polyp, or malignancy.  Bioply may be considered for further evaluation.
The cyst could represent a resolving hemorrhagic cyst.  Follow up U/S is recommended in 6 to 8 weeks for further evaluation.
My questions are:
1. what is within normal limits for my age for the endometrial stripe?
2. Is this Hypoechoic Lesion something to be worried about(cancer)?
3. Why couldn't they find the left ovary?
Thank you for taking this question..maybe someone else has a similar concerns

[SimplyStar]

I would not wait for 6 to 8 weeks,  the cyst in its self is almost to the point of removal, I would get a second opinion,  did you ask why they could not see the other ovary?  If they made the remark in the report about a possible malignancy this should raise a red flag to get an anwser ASAP,  97% of all tumors/cysts are benign but is the slight case yours might not be, it is much better to catch it early.  Ovarian cancer caught early is 90% curable.  Good Luck  As one lady on here says  "You only have one chance to catch it early"