Pheros can have marked self effects, yes but this differs widely between individuals, some get them very strongly and others very little. You can also get used to them very quickly if you use that phero a lot - IS is one of the worst for this. I would strongly suggest that you don’t choose pheros for potential self effects - rather, look on them as a pleasant bonus if you do get them. 
I agree that Twilight sounds like an Androstenone OD to me - The responses are just what you might expect from young women around a young guy wearing the stuff. Now you are 21 and if you have any left, it might be a different matter - A woman gets used to more overt/stronger none as she ages and as you leave puberty in the past, you produce less of it, so it becomes much easier to wear. I would still leave it (or TUTH) for the clubs/raunchy places though rather than work/college but maybe moderate it with something social and pleasant like IO and IS.
Oh and I do know Finnish clubs - I worked in Helsinki and Jyv?skyl? when I was in my twenties and I must say that had a whale of a time. Finnish girls were an eye-opener to this lad from the bleak coast of Scotland! 
:o 
For more general wear, Ammo is indeed a good choice and IO is good to help promote a more social and approachable vibe. IH is better for getting to know/get close to someone and I prefer the IH/IS combo for its more mature conversation vibe. Put bluntly - IS is one of the most useful and widely wearable pheros sold here and it goes well with so many products!
Basics on the different types of Ammo here: