Why is he so quiet with me? And what do I do?

i recently started dating this guy.. he was really chatty and flirty prior to the dates and then throughout the dates he was also.. he also made all the moves and kissed me at the end of the first date... and we slept together on a more recent date

we had such a lovely evening .. and things did go how I wanted them too.. the day after the more recent date he was starting his first day at a full time job so hasn't had a lot of time to talk or see me...

i don't kno what to do.. am I being silly because he has been busy and tired so its not me.. its just him.. or am I not being silly at all! also what shall I do? do I confront him.. keep persisting with chats.. or let him come to me... or other? please helppp xxx