Sorry if tmi here-
for me af cramps feel looser in general, accompanied by looser bowels movements. Cramps can become painful, but not always, maybe headaches but not always. They make me want to lie down. There is a general feeling of 'looseness' and 'falling out' feeling-this is just before af. Sometimes slight nausea.
The cramps around ovulation are not really painful or unpleasant, just present, noticeable. Im feeling action in the ovaries so to speak. The cramps (for me they are not really cramps, just sensations) are accompanied by ewcm, as well as slight constipation. Ive come to see that that this constipation is actually cyclical, and is probably a biproduct of estrogen. I can almost predict the onset of ewcm by the feeling in my bowels.
With O, there is a tight but heavy feeling rather than a 'loose' feeling i get with af. As O approaches i feel a heaviness in the ovaries, that can sometimes lead to a quick sensation of pain that is shortlived. It is not unpleasant like af, but noticeable. it doesnt make me want to lie down, but makes me want to stretch a bit.
I hope this is helpful to you. For me the sensation is very different, but i am finding it difficult to describe...
As for the tight feeling you describe, i have gotten that on the odd occasion, but it doesnt last more than a day. It sounds like it could be O, but if it goes on for too long, it might be something else...or maybe in this case your body it trying to O, but just not able to get there for some reason...
...hope others can chime in with something helpful :-)