We've been a bit lax about contraception. I'm exclusively breastfeeding - no dummies, no expressing. However she's a good sleeper and these days generally wakes once for a feed, or not at all. Cluster feeds all evening, sometimes up to midnight.
No periods yet.
I didn't get periods until DD1 was 18m, but she was waking for feeding more often.
Need I take a pregnancy test? Not sure how big the risk is really.
Conversely, my DS is also 5 months, periods not back yet either, he's bf with a daily bedtime bottle since 4 months and the occasional extra bottle if DH has him. We want a small age gap so no contraception, and I'm not pg yet! With my eldest I was bf, my periods came back at 16w and we were very lax about contraception til I got a coil in at 6 months post partum and no pregnancy then either. (For context I've fallen pg very easily every time we've tried). I would definitely sort out some contraception ASAP if you don't want another, but it's not a given that you'll fall pg!
I tried until DD was 6 months to get preg while BF but it just wouldn't happen for me - I wasn't ovulating. As soon as I stopped BF completely AF came three weeks later and I got preg that cycle. DD2 is only two months now but we're not bothering with contraception because I know I won't get preg again til I stop BF completely. My mum and sister were the same. You may be different though!!
I got my periods back when my EBF son was 4 months old and my cycles were regular. When he was 12 months old I had a Mirena put in which I then had taken out just before DS was 2 so we could start TTC #2. I was still breast feeding at this point. I feel pregnant straight away but miscarried two weeks later.
We had another ten cycles of TTC, alongside me still breast feeding, but every month I failed to conceive. DS was only feeding 2-3 times a day and sometimes due to my work patterns he went over 48 hours without any feeds. During TTC I did wonder if me BF'ing was the problem (as we had conceived DS on cycle 1) but I hadn't really wanted to stop but after the tenth failed cycle I decided to stop BF'ing to see if it made any difference and lo and behold I got my BFP the next cycle.
On the flip side lots of women get pregnant whilst breast feeding so if you have sudpicions then definitely test and good luck if it's a BFP that you want.
I'm part of a group which has loads of tandem nursers in so quite likely! I think the perceived wisdom with bfing is you're ok for 6 months but that's based off baby going for 6 hour stretches. My friends periods came Bacj at 6 weeks pp despite the fact she was feeding every 2-3 hours. She was not amused