Hi ilikeskittles. I tend to lose track of my long term transits, let alone short term ones, but there have been times when I've noticed that a short term transit has coincided with a 'sympathetic' experience. I've found it particularly with Mercury; I have Mercury in Aquarius closely trine Uranus, and there have been days when a short term Mercurial transit has been happening that my mind has been very active, but I've not been able to focus. As Lin says, these experiences are more likely when the short term transit is acting as a trigger for a long term transit.
It could be that the relationship stuff you mention is also an expression of a 'shared transit' where you and your partner experience a short term transit on the same day because you have a close synastry aspect (and where there is a close synastry aspect between the same factor in each chart, the position of this factor in the composite chart is also transited.)
I've also found that if I feel different for a week or so it can be because a slower moving transiting factor is aspecting a midpoint - these transits to midpoints seem to only operate within much smaller orbs than transits to celestial bodies or angles, but can be very powerful within that range (mainly with the conjunction and opposition, but also with squares and even with less 'fundamental' aspects).
With regard to the transiting Sun opposite Pluto, it might be worth checking out which natal midpoints closely aspect natal Pluto, and also if any slower moving transiting bodies were aspecting natal Pluto at that time. And of course if any other short term transits to other natal factors coincided with it.
Best wishes
Miquar