TTC #2 for 9 months now...

[MitzeeeMoo]

Okay, so i have a 6 year old daughter from a previous relationship (she turned 6 today, whoo!), she was conceived within about 2 months MAX.
Been with my new partner for coming up to 2 years in March & we've been trying for a baby since March just gone.. (when i say trying, i mean, having sex unprecedentedly & just going with the flow)

Well, the "going with the flow" attitude is getting me a little stressed out as nothing has happen. Came off the pill in March, got my first AF in April.. for a couple of months it was getting back to normal (normal for me anyway as i'm irregular). During June-July-August i was having a normal 28-31 day cycle.. until last month. We were BD'ing (eh hem) exactly a week before my AF was due, & after BD there was blood, bright red. not a lot but more than just spotting. Went to the bathroom & nothing, for next couple of days was brown, then back to red & sort of like a very light but strange period for 5 days. When AF was supposed to be due the following week, nothing came.. so i assumed it was just an early AF. Which i'm freaking out because surely that's not right? Has anyone else experienced this?

Anyway, that was last month, i have a period tracker on my phone (app) which says my typical cycle is 31 days, i should have been on yesterday which i didn't. BD'd last night & afterwards noticed the minute bit of blood you could think of which was brown.. nothing since.
My body likes to play tricks on me, makes me start believing maybe i am, then AF will turn up un-announced a week or 2 later with disappointment.

I'm just a little worried as to why it's taking so long to get pregnant. I'm 24, Fiance is 23 & this is my 2nd child, his first. He is a chef, we both smoke, we both don't eat a very well balanced diet as both work silly hours so never find the time to cook a proper meal (diet consists of super noodles & microwave food). Is this why?

Should i be worried? Should i maybe see a doctor or is it early days?
Has anyone experienced any of the issue's above & do you think it's likely i'm pregnant now? (Leaving it till Monday to take a test)

Please, any advice would be gratefully appreciated, sorry for the long message x