During the day it is easier to get distracted. Whether or not we always want it to, life goes on. We still have to take care of the kids we have, take care of the house, pay the bills, etc. The grief is still there, but you can move it to the background for awhile, let it simmer on the back burner while you go through the motions.
At night it demands your attention. For the first week after it happened, I went to bed at night and the tears just came. My husband just put his arms around me and held me while I sobbed for hours at a time. He usually ended up crying with me.
Weeping should be listed as one of the side effects of an ectopic pregnancy.