When can I ??

So I'm really new at ttc. But we've been trying the last couple of months. But I haven't gotten these symptoms until the last week or so: my breasts are sore, my lower back is aching, I started spotting today( or maybe it was implantation??) but it went away almost immediately, and I've been having trouble sleeping at night because my tummy kinda feels like it's "sloshing" if that makes sense??i don't know if I'm pregnant or not.  I don't know if us wanting a baby is making me have a hysterical pregnancy. Which I know a lot of people will say "just take a test". Which I intend on doing tomorrow but when is the best time to take a test?? I never know if it's too early to take one or what bc my periods are irregular.