Not ovulating?

So I’m trying to conceive. I’m 40. I’ve been using clear blue digital (one with smiley face etc) I’ve not ovulated at al and I’m due on in a week or so. I only been getting the circles and it’s not gone to smile at all. I don’t understand it. When I’ve used the strips it tad darker. So not sure if I am or not. I’ve not used any contraception for two years and not conceived and only started using ovulation bits for 5 months. Strips I’ve ‘had positive’ ovulation and now using these clear blue I am not getting anything. What do I do? I’m not sure