Getting pregnant

After coming off the pill to give my body a rest I had my first period after 42 days. I am now on day 14 and had intercourse I've done a ovulation test and it says I'm not ovulating. What are the chances of me getting pregnant ? It wouldn't be a big thing if I was but wish we had used something now as I'm not sure if I'm ready. How long after intercourse can I do a first response ? 4 weeks ? Don't really know my cycle pattern at the min as I was on the pill for 16 years.