Saying I love you

So my boyfriend and I have been dating for 5 months now and I’m ready to say I love you to him but I don’t wanna be the first. Before me he dated a girl for 8 years and found out she had been cheating on him for the last 2 so his trauma is real and at times he tells me he has worries but not to take them personally cause he really likes me. When did everyone else saying I love you in their relationship??