Do You??

You can try any of these:
1. Check for malware. Malwares usually stick with the files you download just before the random ads start coming. You can look at your download folder and see if there is any unwanted file there. Usually I sorted the files based on the date so that I can check if any of the files are malwares. For example, I downloaded a picture from a website, but instead of loading one file into my download folder, it also downloaded another file (usually it has a weird name like 1234566.exe). Delete that weird file.
2. Activate your antivirus and focus the scan on the folders you usually direct your downloads to.
3. If you use windows, check your control panel, click on uninstall a program, sort the list of programs based on the date it was installed on, check if there is any files you know nothing about, sounds suspicious, or had just been downloaded before the ads started coming. If you found any, uninstall it.
4. I heard mangago has lots of ads, naturally. If the ads didn't happen when you visit other sites, this is most likely the case. Download an adblocker, it will stop any ads on any sites (except for a few).

Not mine. Idk about others

Maybe you accidentally click the ads ?

Here in mangago, I don't receive any ads though. But in myreadingmanga site, ads always appear on it especially when I clicked a manga. Idk why but I always ignore it and cancelled it. Is it a big deal to receive ads ???

Yea in myreadingmanga, its redirecting 4 out of 10 times i clicked,, hmm its annoying if the ads appears for 4 times maybe? And its kinda makes me jump because its sneaky, makes me think its a virus, click back button and youll never return, need to close it., its annoying for me if the manga redirects to another page and i have close the searching algo. Means i need to search for the tag again on whichever page it is. (〜￣△￣)〜

Yea that's what I mean. It's happening to me and I wasn't sure if I was the only one