You wrote this about the 1st of May, so if you wrote down her last day of bleeding - lets just say it was April 20. False pregnancy usually follows the whelping chart, so 63 days would be June 22. I would make sure she has no toys, and not allow her to lick her teets (that will increase milk production). If you have a training, walking or playing routine, stick with that and do a bit more to keep her distracted on real life, not the one her body is wanting to do. It IS real, the hormones are going through the exact process as if she were pregnant, so it's easy to empathize, but the more she acts it out, the more she will go into that mode. They are all going to be different, but mine came back to earth about a week after her "whelping date". Like puppies happened, but didn't survive: nothing to lick, nurse or watch over. Again, real hormones - no pups to nurse, the teets returned to normal. Mine quit nesting her bed (that was actually funny - she would circle dozens of time, pulling blankets every which way and she'd become a bit obsessed with it, so I'd tell her to stop & lay down. She also snapped once at the other resident dog which she'd never done before.
There IS a drug - I can't recall the name - that your vet can give you to make everything stop in a hurry, but it WILL go away with time and other than being a pain in the butt, it doesn't hurt anything.
I also read an interesting study I should find and post on the forum about spaying. Basically it said to be sure to spay when they are in complete anestrus. Not coming in, not going out, not during false pregnancy. The study said you could "lock in" that hormone level. It doesn't make sense really when I say it that way, I'll have to try to find it. But I do remember making a note to myself that if I were ever to spay my dog I would make sure it was during her anestrus months.