I think to your concern I could find half of an answer because I still have no clue about the order of surat al-Qalam. There have been two periods of silence.
After the first period of silence which was right after the first revelation of surat Iqra' (al-'alaq). And this period ended by the revelation of some verses of surat al-Mudathir, as stated in sahih hadiths on the authority of 'Aicha and Jabir ibn Abdullah.
Sheikh at-Taher Benachour (or ibn Achour) in his tafsir quoted that the verses from verse 74:34 on are probably revealed in Medina.
He also discussed the saying of the Jabir ibn Zayd (also known as abu a-Sha'ata' student of ibn 'Abbas, the jurisprudence of the Ibadi sect is based on his fiqh) who said that the order of revelation was: surat al-'Alaq, then surat al-Qalam, then surat al-Muzzamil and as the 4th surah surat al-Mudathir.
Saying that the sahih hadiths contradict him clearly and surat al-Muzzamil can't be revealed before as the way Allah addresses the pagans there is more severe, detailed and explicit and as major reason he quoted that prayer was ordered after a longer period of silence, so how could Allah address it in such an early period of revelation. It was said that this first period of silence toke 40 days (note that there's a dispute on the length of this silence, some even quote ibn Ishaq and say it was for 2.5 or 3 years). All this seem to fit with ibn Ishaq's quote and order of what happened according ibn Achour.
Ibn 'Achour also pointed at something which one might take into account: some scholars like ibn al-'Arabi and ibn 'Atiyah called surat al-'Alaq surat al-Qalam and surat al-Qalam surat Nun سورة ن or سورة ن والقلم.
Note that the first revelation was 96:1-5 only, so the surah was not revealed at once, as we can find in sahih hadiths!
Then there have been a 2nd period of silence as stated in sahih hadiths like in al-Bukahri and this, I've lately passed by strange and less reliable similar narrations whom even named the woman who addressed our Messenger, some even pretended it was his wife Khadija (but that seems to me a very weird and untrustworthy statement).
See also this fatwa for more information.