I was very happy when my first and only offer came in my email today, but now I'm really worrying and get stuck in an dilemma. They asked to reply whether accept or withdraw the fellowship asap, "preferably within ten days of receipt of the notification"!! They also said "cannot guarantee funding will be available after April 15, 2016". The situation is I'm still waiting for other programs' interviews, and have no idea whether I would get other admissions, but this offer is not in my top list (unfortunately is at bottom among my applications). What should I do then... I'm really losing my calm now! Could I just wait for the other applications and reply to this offer sometime before April 15? Would that influence the fellowship thing? Thanks very much!