I have PMS synptoms a lot of bloating slight cramps sometimes, back ache. No period for 3 months very irregular ttc 2 years?

Evaluation. Sounds like your hormones are fluctuating, but not as they should. Either you are not ovulating, or something may be blocking the period from coming out. If it has been 2 years of trying to conceive, you should see a fertility specialist since that is most likely related to the change over the last 3 months of no periods.
See medical care. Skipping periods for several months can be due to thyroid problems, ovarian cysts, endometriosis or other problems. Bloating, cramps, back pain and infertility can also be a sign of endometriosis. Infertility evaluations should be performed if you have been trying to conceive for 12 months or longer.