How many marrows should I get

I have three marrow plants on my allotment and so far have picked three marrows one from each.Two of the plants have another marrow ready to pick.This is the first time I have tried marrows so not sure how many to expect,There are still plenty of flowers on the plants so does that mean I should get some more marrows

 

Should keep cropping as long as you pick them off, it'll give up if it thinks its set seed.

Might need a liquid feed though