TTC & Overweight

I am 24 Years old. 5'4 and weight 280 pounds. Been TTC for 3 years with no luck. But my cycle is very irregular. Haven't had a period in months!!! Can I still ovulate without having a period?? I've been trying to loose weight but I also have a crazy work schedule But still try to hit the gym in any free time and trying to cut out sodas and eat better. Any advice???!! Help me out!!