New to TTC 🤰🏼

My DH and I have just started TTC...I am 35 so a little nervous I've left it late. Only been using the app so far and as I was away with work we only BD'd a couple of times the day after the app said I ovulated...that was 3 days ago and 4dpo. I am feeling oddly gassy and definitely crampy. Considering we missed actual OD could I still have conceived??