I had my AF on 12th November till 16th November, which means I should have O'd around 25th? I've had sex every 2 days since the 18th November, since I O'd I've had tender breasts and mild cramps in my lower abdomen, I feel slightly nauseous and it seems that no matter how much I eat or drink I'm still wanting more! Could I be pregnant?

It's possible, but the egg would not have even implanted as of yet so you wouldn't be having those pregnancy symptoms.

It is likely that you did not ovulate around the 25th. Many women do not ovulate 14 days from the start of their period. A better starting place would be about 12-16 days before you expect a period regardless of how long a cycle is. That is just a starting place however.

Are you still having regular sex? It may be the changes are due to your body preparing for ovulation itself. If at all possible, have the regular sex from the last day of your period throughout the cycle. Keep in mind that timing is just part of it however. How long have you been trying?

See what happens when your next period is due and try a test if need be. If this wasn't the month for you, I hope it happens soon!

Yes I am still having regular sex, for about 2 years now, every month I end up dissapointed! Fingers crossed this month will bring excitement