The Celebrity Big Brother winners were briefly living apart after a "catastrophic" argument, prompting fears that their 13-month relationship is on the verge of collapse.
Houghton has now insisted that the couple are strong again after "the worst three weeks ever" and echoed Reid's frustration about the press publishing false reports on their relationship.
"After the worst three weeks ever, things are a lot better between Alex and me," she wrote in her New column. "Any suggestions in the press that I know my relationship with Alex is over are completely untrue.
"For a time, my mind was focused on all the other stuff, and I feel sad that I'll never get that time back."
The pregnant star also admitted that she has become "petrified" of giving birth to Reid's baby as her due date this month approaches.
"I've been in a lot of pain because the baby's legs seem to be pushing against my hip bone," she explained. "On top of that, I'm tired and I feel quite sick all the time.
"I was convinced I was going to give birth the other night. I woke up at 3am and thought, 'This is it'. I was boiling hot and felt sick. I was so tired, I was thinking, 'Please, just one more night's sleep and I'll do it tomorrow'."
Houghton and Reid became engaged on live TV back in October.