It could still be from the Depo. Fertility may take up to 12 months to return after being on Depo. If your periods remain irregular after this time then a workup to determine the cause would need to be done.

It does sound like you are not ovulating. Normal menstrual cycles should occur every 21-35 days and usually lasts between 2 and 7 days. Periods that occur less frequently may signify ovulation is not occurring regularly. If pregnancy is ruled out, several factors can be the cause including PCOS, thyroid abnormalities, advanced maternal age, prolactin abnormalities, primary ovarian insufficiency, hypothalmic issues. Its recommended you receive a complete workup to determine the cause. In some cases medications used to induce ovulation will be recommended.

The common ovulation trackers measure an LH surge 24-48 hours before you release an egg. Women with PCOS often have high or eradic levels of LH throughout the month, making it a poor predictor of ovulation. Ovusense published research on using their ovulation kit with 99% accuracy for those with PCOS.

Yes, though you might need IVF with genetic testing of your embryos, or IVF with an egg donor if its determined your egg count or quality will not produce a live birth. The risk for genetic conditions increase with age, as does the miscarriage rate, while your chance of conception without medical assistance declines. Pre-conception genetic counseling screening is important as well as a telemedicine consult with an IVF specialist so you can assess all your options and determine what diagnostic tests you can complete right away (ensuring your tubes are open, no uterine abnormalities, fertile hormone levels, etc).

It is true that high body weight causes hormone disruption in both men and women making not just conception difficult, but carrying a healthy pregnancy to term difficult. It's also true that some women with high BMI go on to conceive without assistance and without complication. Even if it seems like everyone overweight around you is having babies without issue, its the rarity, not the norm. Excess weight in men can reduce sperm count and quality, as well as lead to ED. Excess weight in women can prevent ovulation. Certain ovulation induction medications and IVF may be dangerous if your weight is too high. It's important to work with a clinically proven weight management program to lose weight in a manner that is healthy and supports metabolic balance.