It could be a clogged print head that gets some ink out and then clogs then lets it out again
You can fix that by using the Automatic cleaning routine on the printer menu on the printer itself. It is usually under ink or maintenance or tools.
What is not as common but seems to fit your description better is some printer cartridges have a vent on the cartridge to allow air to get in to replace the ink that is going onto the page. If that vent is clogged than it will put some ink out and then when air does not come in fast enough it creates a vacuum and cant get ink out again until more air comes in and then it prints again. etc
if you tell me what printer it is i can find out where the air vent is. But it is usually just a pin hole or slot on the top or back. pushing it with a paper clip usually clears it. Or you could just try a new black cartridge.