11DPO negative, so discouraged

Has anyone had a negative test at 11dpo and still turned out to be pregnant? I am feeling very discouraged. I have been pregnant 3 times, 2 miscarriages and one healthy baby boy who will be 2 this month. All I want is to give him a sibling.

I'm 35, and we started trying in July. I got pregnant right away, but miscarried at 5 weeks 2 days. Since then I have ovulated every month, and we are actively trying every month, but nothing.

The first miscarriage was right before I became pregnant with my son. The miscarriage happened at 4 weeks 4 days on January 21st 2018, and I got a positive test on February 16th.

I just don't understand why it's harder this time around. I always heard getting pregnant was easier with the second baby.

Any words of encouragement would be appreciated at this point. My husband's birthday is this Saturday and I had really hoped to be able to surprise him with a positive test. 😔