1.5 gallon to a 5 gallon for flowering

if I have a plant that is flowering it's in a 1.5 gallon pot then I transplant it to a 5 gallon pot as it is beginning to flower, how do you think it'll do? I am putting organic nutrients in it, blood meal and bone meal and maybe some fish emulsion here or there. It's only around 10 inches tall and has been flowering for about 3 weeks

I'm not so sure that a 10 inch tall plant needs larger than a 1 gallon pot to flower in. If you transplanted properly it shouldn't hurt the plant though.

I heard that it'll double its size when it goes into flowering, I didn't expect it to be really big because I wanted it to go into flowering so I could harvest sooner but now that I have another one I was going to go ahead and let it get bigger then harvest later on.

Actually from my experience, after the plants are started to bud out, the roots stop to grow. I know this because Ive had several potted plants that I forgot to get around to transplanting into the ground before flowering. All the plants were definately rootbound in 3 gallon pots, And they were all approx third week of flower, I stuck them in the ground, they took off great. It wasnt until harvest when I pulled up the plants with the roots underneith, it still had the original shape of the 3 gallon pots, meaning that the roots did not continue to grow down or out any more after flower. But yea dude, since you already transplanted then your good.

ya i beleive the roots stop growing also , i transplanted a plant after one week of flowering and i noticed alot slower growth for a couple more weeks though