If you take a pregnancy test, you'll know if you are pregnant or not. Are you having unprotected sex?
It could also be perimenopause, the odd ball time leading up to menopause that can last for a decade. This is the time when our bodies go through major changes. Weight gain. Wonky periods. Night sweats.
Just like when we start our periods as teenagers, there is no 'set' age on when we'll start going through the 'change'.
This sounds a lot like what you are going through.
However, if you are having unprotected sex, there is a possibility you could be pregnant.