We need more info to better answer your question. Stats? Cycle history(I'm assuming this will be the first bc you asked this question)
Genericly I will answer: I would never run nolva during cycle. True, it has been around for years and does the job, but this is more of an old school technique to manage estro. We now know that an ai such as arimadex or areomasin are best for controlling estro. Save the nolva for PCT.