By the 12th day of your period? I'm assuming that mean cd12 (cycle day). As in cd1 was the day you started your period. If so then that could well be a good time to have sex. It all really depends in how long your cycles usually are. Women ovulate mid cycle. So for example if you have a 28 day cycle, you usually ovulate about cd 14...so having sex every other day leading up till that day and then again after is a good way to try conceive. Sperm can live in there for 5-7 days so it's good to have it before ovulation to the egg is ready to catch!
me and my husband had unprotected sex on 12th day of my periods.. are tell there any chances of getting pregnant??
Any time you have unprotected sex you risk getting pregnant so that's always a possibility. I would wait another few days and see if your period appears. I doubt you are pregnant since it was right before your starting (but anything is possible). If in a week your period still hasn't arrived you could take a test.