My boyfriend and I have been trying to get pregnant since last October and nothing. We already have a four year old daughter. Is there anything I can do to help know when Im ovulating?

My OB/GYN had me go for bloodwork like a week after what my <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period app</a> said I was ovulating and she couldn’t detect it so I’m not sure if there’s anything else I can do at home or what are some signs?