It looks to be doing fine you could give it a feed with tomato fertilizer ( directions on the bottle) pinching out the top will give side branches that you could then pinch out, pick your cucumbers regularly and you'll get lots more--- well done---

Cool, thank you

the other thing i just thought about is the flowers, if its an all female variety each flower should have a tiny cucumber behind it if any havn't-- you can wait until the flower just opens to be sure--remove them, they are male flowers and can make the cues bitter,because they are inside a gentle misting may help the fruit to set--- see how it goes :o)

That's great. I do have flowers with and without.

I have pinched out the top. How do I recognise side branches please?

they'' come out of a joint , now you 'stopped' its growth it will start to bush out and each shoot will look like the top one you've jut removed, They should, as they grow have cucumbers on the branch as you have already, I'd not let the side shoots go too far as you'll not be able to see out of the window!! to support this growth it will need to be fed as reccomended but the pot is quite small so go for quality and not quantity , pick the first one when its just big enough for you and it should taste sweet and crunchy--- do let me know !