Jana Kramer is expecting her second child.

The former 'One Tree Hill' star revealed her's and husband's Mike Caussin's baby joy on Instagram on Monday (25.06.18), and credited the Ava bracelet, which tracks ovulation, for helping her get pregnant after suffering multiple miscarriages.

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.''