I always had an issue with Pentecost being 50 days past "Ascension day" because Acts One verse 5 in your linked source states, "...not after many these days".  You missed the word "Not" in your post.

 50 days is way more than not many. 

I see Barry Awe's vids, and the chapter in Leviticus that looks like another 50 day span is added to the omer count.

 That count has to do with the making of the two loaves from the harvest for Shavuot, another 50 days added seems unlikely to me.

 It sure would be nice to be called up in June (smile).