Trying for a baby..

So me and my boyfriend have been together nearly 3 years we have a little girl who is now 18 months we got pregnant in the first 6 months but I have been pregnant this year again and unfortunately lost our baby! We have been trying for about 3 months now and still nothing I’m getting the same symptoms I had with my little girl and nothing I’m tracking my ovulation days and everything I don’t know what else to try I went to see a nurse couple weeks back I was late on my period and I was bloating really bad and sore boobs and leaking also! She done a test and it was invalid she reckoned I was very early in my pregnancy so I carried on how I was and then came on my period since then we have constantly been trying and hoping for another baby! And just nothing it’s upsetting but we will get through any suggestions on what else there is to help?