I thought Alfie was saying that they weren’t having sex at all in the first trimester as it seemed so weird for her to include in her video at the time (this was in her 1st trimester overview vid.
Also, maybe there is the possibility that she is holding back a bit longer if Poppy has been through something pregnancy related which was the feeling I got from her absence explanation. Maybe she is waiting as long as possible to announce from that aspect? Also I remember Zoe complaining for a long time when she was pregnant with Ottie that she wasn’t showing at all and she was really far along so it could be a possibility she has been pregnant from Dec when she was napping loads and really tired (and why Alfie didn’t mind editing her vlogs etc.) but now shes gone silent as she has started to show after 4/5months but she hasn’t been able to say anything as Poppy has suffered a possible miscarriage around the time she was llanning to announce so she felt bad doing it. So she has taken to hiding now as she is showing bur can’t announce until a bit later