Series 2 episodes badly edited. WITH SPOILERS

I'm watching series 2 and the events in episodes 2 and 3 and 4 are jumbled up. In 2 Mary is very pregnant, while in 3 she just finds out she's pregnant. At the end of 3, she decides to separate the three households till the wedding, while in 4 they haven't bought the new house yet. And these are not he only things out of place. The episodes just don't flow as a linear story line. The episodes don't make sense. It's like they were edited by a crazy person. Is this the way they ran on UK TV?