I got my period but before, during and after it i've had several pregnancy symptoms e.g nausea, eating lots, backache, mood swings, fatigue etc??

Just goes to show ya: Hi. That's a perfect demonstration of lack of specificity of symptoms. No symptom is specific for one and only one condition. Therefore what you're calling "pregnancy symptoms" are also symptoms of something else, since we know you're not pregnant. Don't forget, pregnancy tests are available over the counter if you ever want objective evidence of pregnancy or lack thereof. Good luck!