19 TTC With Irregular Cycles and Need Advice

Hi! My boyfriend (24), and I have been trying to conceive since October with no luck so far (except for a possible miscarriage; hospital could never decide on if it was or not). My cycles are irregular, and I've gotten my hopes up many times, bought tests (negative of course), and had my period 3-4 days later. I don't cramp prior to, or during, my period, so that's never a warning sign. My boobs/nipples stay sore, so that's another thing. I know all the signs of pregnancy, many of which can be confused with a period too. Any advice on conceiving and stop confusing the rag for a  baby? It's very disheartening.