Contraceptive injection

I had the contraceptive injection in December 2016 and it was due again on 22 march. Have been TTC since then. Had my first period this month since December (apart from spotting in January) because it messes up your hormones for a while! does a period make it more likely to get pregnant? Me and my fiancé are so desperate for a baby we have everything we need for the little one and we're not even pregnant yet!