Dumped Sister

My sister Irene 26 was dumped by her boyfriend who then moved away, to add to her misery she missed her next period. Thinking she might be pregnant only added to her miserable outlook on her future. But she had forgotten she was on a medicine that had a side effect of delaying periods in some women while they were on it. She was one of those women, but as she had forgotten what the doctor had told her she thought she must be pregnant. But as she had stopped taking the medicine she just had to wait until it cleared her system in a couple of weeks or so. But having forgotten the doctor's information on possible side effects. She off course when for the worst possible reason for not having her period. Being pregnant to someone who had dumped you. I'm her older brother two years old during well career wise not great in relationships. Another result of her breakup was needing a new place to live, so she came to live with me. As a result, she caught me masturbating when I thought she had gone out. Unknown to me, she had gotten a text message cancelling her meeting her friend. So, she came back, I'd heard her go, but not her return. So, when she came to enquire what I wanted for dinner, she caught cock in hand as they say. Not having had sex for a while and thinking she was already pregnant. She offered me herself to give my hand a rest, shocked at first but also thinking my sister was already pregnant. I thought might as well and agreed, the medicine stops periods not pregnancies. So, with us having sex multiple times, she got pregnant. Of course, we only found out of her mistake a week later via a text from the doctor's office asking her if her natural cycle had restarted. Realization dawned on her, remembering what her doctor had told her about the medicine. But it didn't sex between us as we were enjoying the sex, only we now took precautions. But as they say it like shutting the gate after the horse had bolted. She got test kits and at first nothing showed, but later on a positive result was confirmed, too late to have been her ex-boyfriend. Our state bans abortions and our family beliefs don't agree with having them either. Raised always to that ownership of your actions, my sister and I are now awaiting our daughter's arrival. All medical checks show no problems; we act as man and wife only family know of our actions. Not overly happy with our actions, but happy to be becoming grandparents. We still fuck and are quite happy with our actions now we've come to terms with everything.