Firstly BIG congrats in your suprise bubba! I hope the shock is wearing off and you are able to just enjoy it now.
It took us 4 years and 4 rounds of IVF to get DD and although we didn't want to have any fertility assistance again, we were happy to just let fate decide. The only thing we did was recommence acupuncturist as I had done it for my first pregnancy. We did have DH sperm tested again to make sure and it came back with worse results (when we did IVF he was fine).
The month I got my BFP we only DTD twice. We had all had colds and eaten badly. I was doing a course and working so we were super busy too. I was nearly 5 weeks before I thought to do a test and was so doubtful about it that I did it whilst at the shops in public toilet cause I kept forgetting! Well you could have knocked me over with a feather I was SO shocked!
I just kinda never expected it to happen naturally. And when it did I was excited but had no idea what to do. How do u have a baby normally? Lol. Anyone who has done IVF will understand what I mean by that! So rushed to my GP who knew all my history with DD and so she accommodated my requests which must have seemed about crazy. I had bloods done 3 times 5 days apart to check that my levels were rising (they were fine) and to check progesterone levels (this had been a major problem last time but it was fine) a heart beat scan at 7 weeks ( of corse this was fine too!) and then just nervously waited until 12 weeks scan.
I am now 32 weeks with DD#2 an I have relaxed so much since then. BUT it did take a awhile to get my head around it and how it happened so easily this time. The big question of why? The only thing I can come up with is that babies come to us when they are ready and the time is right, clearly we have no control.
I also have a good friend that had no trouble conceiving her DS and it was taking ages TTC #2 so they went to FS and got tests done. Turns of she has blocked tubes on both sides and his sperm was really bad. He told them there was basically zero chance if natural conception and that it was a miracle that they had DS. He sai only chance of another bub was IVF. Needless to say they were gutted....then she looked at her dates and realized she was late. Did a test and BFP! So she was pregnant at that FS appointment and didn't know!
Miracles do happen and they can happen to anyone! :-)