Internet speed fluctuating problem

My laptop is old and the Wi-Fi card (or IDK what they call it I'm not that tech savvy) baerly works so I'm using a wifi dongle. It seems to fluctuate a lot, between 10Mbps and around 150Mbps. Sometimes the upload speed is nearly as much as the download speed which I've never seen before. If any of y'all would let me know if that is a problem too that would be great. I bought a USB hub so I can plug more devices like mouse and keyboard in my laptop ( I don't know if that affects anything I tried the wifi test with and without it and it doesn't change much as far I noticed) I have no Idea why this might be happening but it's definitely odd.