Plz help.. I think I am not ovulating😩

Angelica

I have been tracking my ovulation every day for the past 2 months. At least twice a day. I have not had a positive ovulation strip yet. I haven’t had a period since December. My period is very irregular. I didn’t have a period before the December one since June of 2017. We have twin girls. Which I didn’t not know I was pregnant with until I was 3 months. Since I wasn’t having a period I didn’t think I would be pregnant. This was in 2015. They are now 2. We have been trying since January to get pregnant but nothing. 😢 we really do want another baby. What can I do to up my chances in getting pregnant again?? This is the brightest it’s ever been.