Missing Periods. HPT Negative. Feeling Bloated. Worried For Ectopic Pregnancy Or Ovarian Cancer?
Given how late your cycle is, and the negative pregnancy tests, it is almost certain that you are not pregnant. What you are likely experiencing is an "anovulatory cycle". Normally, when you ovulate, there is a predictable withdrawl bleed about 2 weeks later. When you don't ovulate, this bleeding does not occur and can be significantly delayed.
Certainly one cause might be a persistent functional ovarian cyst on the left. This would fit with what you are describing. You need to:
1. Call your OB/GYN for an appointment
2. Ask for an ultrasound
3. Ask about using a 10 day course of progesterone to induce a period
4. Ask about ways to regulate your cycle
5. Ask about birth control (if you are not on any)
I hope this helps and good luck!