Apart of the government's response to the coronavirus pandemic was to inject $1,200 checks into American's pockets that were eligible. Another aspect of the response by the government was to increase unemployment assistance.
All of this response by the government came under the CARES Act that Congress pushed through in March. Apart of the CARES Act was the increase in unemployment benefits, which saw a $600/week boost in unemployment insurance. At the end of next month (July 31) this benefit is set to expire, but by then, we can expect a second stimulus check to be rolled out, find out more on that here.
In the meantime, it should be noted that if you haven't claimed the $600-per-week unemployment benefit for the weeks between March 28 and July 31, you might be able to do so as back pay. According to The Penny Hoarder, "Individuals that qualify for the (Federal Pandemic Unemployment Compensation) $600 payment for weeks they are eligible ... can be paid, even if not approved prior to the (July 31) deadline".
This means that if you haven't collected the unemployment benefits, you can claim for all the weeks you have missed between March 28 and July 31. If you were out of work for the entirety of that time, you are eligible for 17 pay periods, which equates to a total of $10,200.