A colloquial expression meaning 'since a short while ago' or 'for some time' — commonly used in conversation to indicate continuity from a recent point until now.
さっきから隣の部屋で工事の音がうるさいんだよ。
The construction noise next door has been loud for a while now.
さっきから彼女に何回もメッセージを送っているのに、返事がない。
I've been sending her messages repeatedly since a little while ago, but there's no reply.
さっきから体調が悪くて、少し休んできます。
I've been feeling unwell for a while; I'll rest for a bit.