Can I be pregnant again?!?

I had a miscarriage in March, I haven't been on the pill since December, me and my ex had sex a few weeks ago he didn't use a condom but he pulled out, this was during the time of my ovulation. But he pulled out, I was supposed to start my period like 2 days ago, and there's nothing, the last time I was pregnant I caught it the day I missed my period, well I've been moving from another country where the time goes 8 hours back in time. I flew the day my period was supposed to start on an 18hour flight, normally I ALWAYS start when I'm in flight or traveling but not this time, could this trip be the problem or am I expecting another baby?