period late

Louise
Been trying for 2.5years, I have first <a href="https://glowing.com/glow-fertility-program">ivf</a> appt booked in June & my period still hasn't turned up. Test was negative this morning, how long should I wait before taking another? 
I'm feeling hopeful but trying not to get my hopes up too much to be disappointed. 
Also have a banging headache 🤕