TTC with kind of irregular periods

[LeahMay]

Can I be pregnant if I had sex a week after my period ended? I know it seems like a really stupid question, but I'm asking because when I've googled it most sites say you ovulate on day 14 of your cycle and I did not have sex on day 14.
So, my periods have always been a little off and I never know how frequently it will come and therefore can't really track ovulation. I DO have a period every month, but sometimes it is two weeks apart and other times just over four weeks apart, and it can last anywhere between 3 and 8 days.
Anyway, the first day of my period was the 14th and it stopped on the 17th. I had unprotected sex on the 24th, which, obviously is a week after my period ended, but because my period didn't last 7 days is not day 14 of my cycle.
I'm not sure if I've worded this well at all, but, the point is can I fall pregnant with this kind of timing? If not, is there any way of trying to track ovulation with my periods not being the same every month.
Please don't just say "you can fall pregnant at any time" as I've had this said to me a lot, I'm looking for realistic chances that I can be pregnant.
Thanks in advance ladies :-)

Possibly- you can fall pregnant at any time of your cycle it's just more common over ovulation

Those sites you've been reading re ovulation happening on day 14 are just plain wrong. Ovulation is not an exact science and this can happen earlier, later or not at all in any given cycle. Having consistently irregular periods means that you are less likely to be ovulating regularly.

I would also suggest you now have blood tests done to see what your hormone levels are like; if these are awry then ovulation will be affected. You initially need a day 2 test done to see what your LH (luteinising hormone) and FSH (follicle stimulation hormone) are like.

You could buy some cheap ovulation tests from amazon and test daily from the day your period ends? Good luck with the ttc