TTC#2 unmedicated after IUI success w/ DS

Hi!

I'm new to the boards, it's been a long time. My DS is now 16 months, he was an IUI success (4th time was the charm w/gonal-f). Now we are TTC #2, and I have only had 4 cycles since I was breastfeeding up until about a month ago.

 Long story short I charted the last 2 cycles and pretty confident I o'd. I am now on CD 30 today and so far I've had 28-31 day cycles and I usually spot the day before. This time, NOTHING. I spotted on CD 18 and since I hadn't started I was thinking OMG I might be pregnant without gonal-f, IUI, progesterone supps.etc. Well, got a BFN today when I tested. So what I thought was implantation on CD 18 maybe was not!

 My question is, could it have been too early to test? I think I o'd fairly early too, so I'm prob. grasping at straws.

 I also have EXTREME bloat which has me a little concerned to be honest. My stomach has just felt "off" these last 3 days and I don't have the usual cramping I have when AF is arriving.

I am so not ready to get back into IF treatments again, but know it's probably going to happen again where I need to....