Why can't I do a test?

Ok so I came off the pill in feb had a 2day light period at the end of my last packet which was lighter n shorter than normal then on the and around my ovulation days we BD then about a week later I had really sore even to touch it's not so bad now though anyway Im four days late but I don't want to test I don't want it to say no I know that must sound silly and I know I'm expecting alot for our first month but for years iv been scared that I can't concieve I'm a petite person 5foot 1 and slim n I guess sometimes I think I'm too small when I tell my family they just say don't be silly (my mum is also small and was slim before having children ) anyway I guess it's just Going to make me feel worse if it says no how do u get ped that feeling and does my frame mean that I will struggle to concieve any advise welcome sorry for essay oh and just incase you wondered I'm not underweight I'm average i'm just patite in frame thanks inadvance