It seems you are running a cycle of Test at 250mg per week... That was my first cycle albeit I used Pharma stuff so it was a legit 250mg dose. Can you grow? Yes, hell yes you can, if you can't you have a clear indiciation of poor diet and training which will need to be addressed.
250mg Test WILL give free test levels that are higher than natural, period. Whether it is a substantial increase compared to you baseline levels is all individualistic, but regardless the point remains.
Bumping up to 400mg from 250mg per week will increase your muscle gain and potential fat loss, RBC count etc etc more is always better for that, but more juice = more sides.
It takes 4 weeks for long estered Test to reach steady levels so what your suggesting won't do a whole lot.
I would suggest finishing up/getting started on PCT whilst doing some research on AAS and diet/training if need be
For future reference, I rec. 400-600mg Test for a first cycle, no more no less along with an AI like Arimidex or Letro to gauge how you respond to test. 600mg for someone who knows how to train and diet, will yield great results from that. Even as a 2nd or 3rd cycle 600mg Test, even 400mg Test will do the job however you can start adding compounds and changing doses after you get a feel for your first cycle. Test alone is a great compound, if you need a little extra kick Masteron Enanthate at 2-500mg per week would make a good second cycle or if test gives you estrogenic sides. For example, Test is great but I suffer from high e sides from it even with an AI so I plan on doing 500 Test 500mg Masteron for my next blast.
Hope that helped, don't be afraid to ask anything that comes to mind, but don't be afraid to research before asking as well