We started trying beginning of August and concentrating on my fertile zone

We started trying beginning of August and concentrating on my fertile zone ... We had no luck. So in December we just decided to enjoy christmas and not concentrate on any specific times but just have lots of sex and so on my usual 1st day of cycle (day 35) my period didn't come but not only that if been feeling really off all week  . Severe back pain, increased  ethargy and abnormally sore breasts. I did 3 tests on 2 consecutive days which had faint second lines so went to my GP yesterday and had a blood test and I'm pregnant apparently approx 3 weeks. We're over the moon just have to get through the next few weeks and hope as is well and healthy. Yay!!!