Not having a period for 2 years usually means that you haven't ovulated for 2 years, since ovulation
is what brings on a period 2 weeks later.
The reason for not ovulating is probably the increased weight. For some reason gaining (or losing) much weight can cause a woman to stop ovulating.
Your doctor can confirm whether you're ovulating or not by a blood progesterone
, since progesterone only rises after ovulation. Taking some progesterone pills for a week or so and then stopping should bring on a period. That will also confirm that you're not ovulating.
If in fact you're not ovulating, then there are 2 ways to start ovulating. One is to lose weight. The other is with pills called Clomid. By taking them for 5 days each month, they will usually cause ovulation to occur. Once ovulation occurs, you'll either get a period 2 weeks later, or you'll be pregnant. Once you're ovulating every month, it generally takes a few months or more to become pregnant.
So I would recommend seeing your doctor for evaluation and treatment.
If you have further questions when you get back, please ask.