Pregnancy Symptoms

Okay, so here's what's going on with my body as of today. MAJOR hot flashes. Nausea. Super tired. Very weak in the leg area. Dizzy/migraine. As soon as the hot flash is over I get super cold. I feel like crap. Basically. Are these early signs of pregnancy? Or is it all in my head. Me and my boyfriend are trying to get pregnant. I ovulated last week. And we had sex that same day. Is it too early to know? HELP