Questions pls ladies

Magen • I'm 26• I have 2 boys 1&6• Stay at home mother
So my fiancé and I were talking about getting pregnant I have a son already prior to meetin him 2 yrs ago and we were thinking of having one also, well we tried for maybe 4 days and I wasn't ovulating so I'm prob not even preg and now he's backing out saying maybe he's not ready and he doesn't want to struggle all his life and he doesn't think I'll finish school if I get pregnant and I'm so upset I've been balling my eyes out about it because I know we will be ok I've told him I would finish and I'm really ready for this another child I have been.  He thinks I'm crazy and it's not a big deal to cry about but I'm crushed.. Any ideas? Advice?