Born to an English father and Finish mother, the full-back donned the Three Lions at under-17 level before switching allegiance to Finland.
Jenkinson represented the Nordic nation up to Under-21s level, but last year elected to make himself available for England.
The Arsenal defender soon made his senior debut against Sweden in November 2012 and is now in line to make his debut for England Under-21s in the European Championship qualifier against San Marino on Thursday.
"It's really strange and it's mad to think I could be playing against Finland next month," Jenkinson said.
"It's crazy, but football's a strange game.
"It's weird how things work out, but it would be a nice experience for me to play against some of the Finnish lads I played with before. It would be good.
"I look back on it as a fantastic experience. I played for England Under-17s and I was third choice at the time.
"I then had the opportunity to play for Finland. At the time I went there I was not playing regularly.
"I was in Charlton's reserve and youth teams and playing international football - there weren't many people in my team getting the experience I was.
"In terms of my career at the time it was great for me.
"I enjoyed my time there but at the same time when England came knocking, I had to follow my heart. I've always felt English at the end of the day."
Jenkinson has been a regular for Arsenal this season and is set to add to his nine appearances following an injury to Bacary Sagna.
The right-back also has a chance to impress with the under-21s, which he hopes will catch the attention of senior boss Roy Hodgson ahead of next year's World Cup.
"Hopefully I'll get games and playing for England at any level is an honour," Jenkinson said of playing for Gareth Southgate's under-21s.
"When I was given this opportunity, it was a no-brainer for me.
"At the end of the day I want to play for England and this is a very close step to the senior side.
"Of course you have to be doing well for your club, but if you're impressing for the under-21s I am sure the message gets back to Roy Hodgson.
"So it's good for me all round. It's good to get games and they're not friendlies either, they're qualifiers.
"It's going to be good for me and I'm really looking forward to it."