Is it possible?!!?

Kay❌
Please don't lecture me!!!!
I'm 15 and I had sex about 4 months ago, I was then a week late on my period so I tested came back negative. Then few days later I came on as normal, and since then my periods has been late by days or weeks but I've then had them as 'normal' But now I've started to realise  I'm constantly bloated, feel sick sometimes. I've also started eating ALOT MORE and I get dizzy but everyone's saying I can't have periods and be pregnant but I'm just feeling as if it's possivle😩
Before you judge I'm a scared teenage girl! 
I am willing to take responsibility and if I am I Will keep the child!