Jana Kramer expecting her second child

Alongside a picture of the pair sat next to a sign, which read "Only child expiring in November 2018", Jana - who already has two-year-old daughter Jolie with the former American footballer - wrote: "#Ad Surprise! We have a rainbow baby on the way & couldn't be more excited! Jolie is going to be a big sister & we're becoming a family of 4! Thanks @avawomen for helping us get pregnant by telling me my 5 most fertile days! #AvaPartner Pregnancy takes a village - Also thanks Bonjesta (doxylamine succinate/pyridoxine HCl) 4 helping me manage my #morningsickness after diet & lifestyle changes didn't work. It's a safe & effective new formulation of the drug combination I took before that's made to work faster & longer. Most common side effect is drowsiness. [sic]"

Jana has suffered five losses in total, her most recent miscarriages happened within four months of each other in October and February last year.

She told People magazine: "I'm so excited. We lost in October and then we did an IVF cycle and we lost in February, so I want to be able to be like, 'Hey, I know it's hard but just try to have some hope.'

"I didn't know I ovulated late and I don't know if it's because my cycles are messed up because of my miscarriages, but it said I ovulated on the 16th or 17th day so that's what we trusted and I got pregnant."

The pregnancy has been tough so far, with the 34-year-old singer suffering the "worst" morning sickness.

She said: "I was in bed for like six weeks straight.

"I felt like I was just doing such a bad job as a mom because Jolie's super active right now."

The couple reunited earlier this year, after the ex-NFL star was allegedly unfaithful and spent time in rehab.

Jana says she wanted to make sure they were both in a "healthy place" before having another child.

She admitted: "We really wanted to get to a place where we were healthy [before trying for another baby].

"We both know that children do not save a marriage."

Jana says Mike has been like a rock throughout the pregnancy, which she admits has felt "more unified" this time round

She added: "The first [pregnancy] was tough.

"He was going through his thing that I didn't even know about, but this time around he's just truly been the greatest support system I could've ever asked for. It feels so much more unified and I love that."