Actually, there are 3 groups of 7 in the Book of Revelation that deal with that period, not 2. There are 7 seals, 7 trumpets, and 7 bowls/vials. The rapture happens after the 7th trumpet, and the wrath follow after this, which is after Christ’s return. This can be seen in the following passage (Rev 11:15-18):
“15And the seventh angel sounded; and there were great voices in heaven, saying, The kingdoms of this world are become the kingdoms of our Lord, and of his Christ; and he shall reign for ever and ever.
16And the four and twenty elders, which sat before God on their seats, fell upon their faces, and worshipped God,
17Saying, We give thee thanks, O LORD God Almighty, which art, and wast, and art to come; because thou hast taken to thee thy great power, and hast reigned.
18And the nations were angry, and thy wrath is come, and the time of the dead, that they should be judged, and that thou shouldest give reward unto thy servants the prophets, and to the saints, and them that fear thy name, small and great; and shouldest destroy them which destroy the earth.”
Here we see again, the “wrath” is associated with the judgment of the dead, which we later see in more detail in the description of the White Throne Judgment. However, the 7th angel doesn’t sound until the end of the 7 year period. This can be seen if you read the earlier part of Chapter 11, for the 2 witnesses will prophecy for 3 1/2 years before being killed, and then their bodies will lie in the streets for 3 1/2 years before they are resurrected, at which point the seventh trumpet sounds the return of Christ.
It’s good to keep in mind that Revelation is not a straight narrative, there are several narratives, some nested within others, so that you can not read it front to back as a simple timeline. You must look for the events which correlate in the different narratives in order to get a clear chronological picture.
The best book I have seen explaining the rapture and how even the early Church was awaiting the return of Christ and NOT judgement, is:
MARANATHA! OUR LORD COME!
By Renald Shopwers
Check it out on Amazon,
also, here is a great series of studies online: