New to TTC! Help!

So this will be our first month actually ttc. We have a 2.5 year old and we ntnp for about 9 months, and then actually tried (only using the Ovia app tracking ovulation according the that) for 3 months when I got pregnant. I just had an early miscarriage this month. I am on CD5 (period+first time bleeding since my loss)

I am just wondering what the luteal phase is? In the picture you can see it says mine is 13 days? And I feel like I’ve heard of people having trouble getting pregnant if there’s is short... but I have no idea what it is and if mines even short😂 Any advice is appreciated! I’m also using opks, they’re being wonky right now from my miscarriage but I’m going to test again in about 5 days (CD10) and hopefully get a positive around day 14 or 15.

If anyone reading this is my cycle buddy let me know!!! Like I said I’m CD5 today!🥰 oh and forgot to mention I also breastfeed my daughter still, it’s been so hard to wean but now that we are finally ready to start trying I’ve been only letting her nurse for naps and bedtime. My periods are pretty regular every month so I’m hoping for the best!!! I am so excited but so nervous about it taking long, and also nervous about another loss😭🌈