Sperm can last inside your body for up to five days. So even if your not ovulating at the time you still can become pregnant.
I had sex with my boyfriend 2 days after my period and now I'm 3 weeks pregnant so yes you can
If you are trying to concieve then I suggest downloading an app to calculate your cycle and ovulation. I did and fell pregnant within 5 weeks of trying!
The best time to have sex is in the fertile week before you ovulate, day before/of/after ovulation.. sperm can survive for a few days so it can be there when an egg is released.
You are not likely to notice when you ovulate, there is no telling signs but you generally only have a 12 - 24hr window to concieve once you do release an egg.
If you were to have spotting around 10 or so days after sex then it may be implantation bleeding as the fertile egg implants into the womb..
I did a lot of reading when I decided to concieve, as I wanted to be successful.. fortunately it all worked out and I am now due with my first child in 3 weeks!
All the best, good luck :)
I also recommend an app to track everything I use myday n it's helped me with all 3 of my pregnancies. It took a while for my third time but I was also getting off birth control n it takes a little longer for me but I'm currently 5+6 weeks