Need ADVICE

I need advice not criticism.. I’ve had sex multiple times all month and now that I’m 10 days away from my period I’ve been extremely tired,, I don’t normally take naps but they have been creeping back in. When I was pregnant with my first I literally slept all the time. I’ve taken pregnancy test and they come back negative which I figure cause it could be to early to tell just yet. But when my period hits I’m not tired.. so this is new to me because I had my daughter 4 years ago. Any advice??