What if... Advice

Me and my ex have been broken up for 3 weeks now, I really miss him and I want to tell him but at the same time I feel like it's too soon to tell him. I also feel like he might be waiting on me to say it first since I ended the relationship.. Point is, I don't want to live with "what if I just told him I missed him.. "What were to happen" you know? We still text here and there and he knows I been hesitant because he's pointed it out. He told me he still cares for me and whatever I say to him is important to him. PLEASE HELP. Should I tell him or not ?