I rung him but he was acting strange

Last night, I rung him around the time he told me to ring him earlier that day and he was like 'hello, i can't speak, let me ring you back later' and I was like, 'hmm?' and he was like 'I'll ring you later' and I was like 'alright' and he hung up

the 'conversation' barely lasted 15 seconds

it was really strange, he's the one who told me to ring him around that time and after he hung up he didn't even ring me back like he said he would

it was his day off work, it didn't sound like he was at home

and I went on snapchat, and I'm scared to look at his story, he was posting one hour ago which means he was up or out late

we can go 2 days without talking because i know he's busy with work but the way he was acting strangely on the phone doesn't make me feel at ease

can someone just reassure me or tell me that i have it all wrong because I'm out here stressing

he's probably going to ring me today and I know I'm going to be moody with him